读书笔记之：数据结构，算法与应用（2）
第5章 堆栈
堆栈是一个后进先出(last-in-first-out, LIFO)的数据结构。
1. 数组实现的堆栈
源代码如下：
View Code 2.链表实现的堆栈
源代码如下：
View Code 3. 堆栈使用
(1)括号匹配
View Code （2）汉诺塔
View Code
堆栈是一个后进先出(last-in-first-out, LIFO)的数据结构。
1. 数组实现的堆栈
源代码如下：
View Code 
#include <iostream>
using namespace std;
template<class T>
class Stack{
public:
Stack(int MaxStackSize=10);
~Stack(){
delete [] stack;
}
bool IsEmpty()const{
return top==-1;
}
bool IsFull()const{
return top==MaxTop;
}
T Top()const;
Stack<T>& Add(const T& x);
Stack<T>& Delete(T & x);
private:
int top;
int MaxTop;
T* stack;
};
template<class T>
Stack<T>::Stack(int MaxStackSize)
{
MaxTop=MaxStackSize-1;
stack=new T[MaxStackSize];
top=-1;
}
template<class T>
T Stack<T>::Top()const
{
if(IsEmpty())
throw "Out of Bounds";
return stack[top];
}
template<class T>
Stack<T>& Stack<T>::Add(const T& x)
{
if(IsFull())
throw "Not enough Memorry";
stack[++top]=x;
cout<<"Success"<<endl;
return *this;
}
template<class T>
Stack<T>& Stack<T>::Delete(T & x)
{
if(IsEmpty())
throw "Out of Bounds";
x=stack[top--];
return *this;
}
int main(void)
{
int x;
Stack<int> S(3);
try {
S.Add(1).Add(2).Add(3).Add(4);
}
catch (...) {
cout << "Could not complete additions" << endl;
}
cout << "Stack should be 123" << endl;
cout << "Stack top is " << S.Top() << endl;
try {
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
}
catch (...) {
cout << "Last delete failed " << endl;
}
}
using namespace std;
template<class T>
class Stack{
public:
Stack(int MaxStackSize=10);
~Stack(){
delete [] stack;
}
bool IsEmpty()const{
return top==-1;
}
bool IsFull()const{
return top==MaxTop;
}
T Top()const;
Stack<T>& Add(const T& x);
Stack<T>& Delete(T & x);
private:
int top;
int MaxTop;
T* stack;
};
template<class T>
Stack<T>::Stack(int MaxStackSize)
{
MaxTop=MaxStackSize-1;
stack=new T[MaxStackSize];
top=-1;
}
template<class T>
T Stack<T>::Top()const
{
if(IsEmpty())
throw "Out of Bounds";
return stack[top];
}
template<class T>
Stack<T>& Stack<T>::Add(const T& x)
{
if(IsFull())
throw "Not enough Memorry";
stack[++top]=x;
cout<<"Success"<<endl;
return *this;
}
template<class T>
Stack<T>& Stack<T>::Delete(T & x)
{
if(IsEmpty())
throw "Out of Bounds";
x=stack[top--];
return *this;
}
int main(void)
{
int x;
Stack<int> S(3);
try {
S.Add(1).Add(2).Add(3).Add(4);
}
catch (...) {
cout << "Could not complete additions" << endl;
}
cout << "Stack should be 123" << endl;
cout << "Stack top is " << S.Top() << endl;
try {
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
}
catch (...) {
cout << "Last delete failed " << endl;
}
}
源代码如下：
View Code #include <iostream>
using namespace std;
template<class T>
class LinkedStack;
template<class T>
class Node{
friend class LinkedStack<T>;
private:
T data;
Node<T>* link;
};
template<class T>
class LinkedStack{
public:
LinkedStack(){
top=0;
}
~LinkedStack();
bool IsEmpty()const{
return top==0;
}
bool IsFull()const;
T Top()const;
LinkedStack<T>& Add(const T& x);
LinkedStack<T>& Delete(T& x);
private:
Node<T>*top;
};
template<class T>
LinkedStack<T>::~LinkedStack()
{
Node<T>*next;
while(top){
next=top->link;
delete top;
top=next;
}
}
template<class T>
bool LinkedStack<T>::IsFull()const
{
try{
Node<T> *p=new Node<T>;
delete p;
return false;
}
catch(...){
return true;
}
}
template<class T>
T LinkedStack<T>::Top()const
{
if(IsEmpty())
throw "OutofBounds";
return top->data;
}
template<class T>
LinkedStack<T>& LinkedStack<T>::Add(const T& x)
{
Node<T> *p=new Node<T>;
p->data=x;
p->link=top;
top=p;
return *this;
}
template<class T>
LinkedStack<T>& LinkedStack<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds()";
x=top->data;
Node<T> *p;
p=top->link;
delete top;
top=p;
return *this;
}
int main(void)
{
int x;
LinkedStack<int> S;
try {S.Add(1).Add(2).Add(3).Add(4);}
catch (...) {
cout << "Could not complete additions" << endl;
}
cout << "Stack should be 1234" << endl;
cout << "Stack top is " << S.Top() << endl;
try {
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
}
catch (...) {
cout << "Last delete failed " << endl;
}
}
using namespace std;
template<class T>
class LinkedStack;
template<class T>
class Node{
friend class LinkedStack<T>;
private:
T data;
Node<T>* link;
};
template<class T>
class LinkedStack{
public:
LinkedStack(){
top=0;
}
~LinkedStack();
bool IsEmpty()const{
return top==0;
}
bool IsFull()const;
T Top()const;
LinkedStack<T>& Add(const T& x);
LinkedStack<T>& Delete(T& x);
private:
Node<T>*top;
};
template<class T>
LinkedStack<T>::~LinkedStack()
{
Node<T>*next;
while(top){
next=top->link;
delete top;
top=next;
}
}
template<class T>
bool LinkedStack<T>::IsFull()const
{
try{
Node<T> *p=new Node<T>;
delete p;
return false;
}
catch(...){
return true;
}
}
template<class T>
T LinkedStack<T>::Top()const
{
if(IsEmpty())
throw "OutofBounds";
return top->data;
}
template<class T>
LinkedStack<T>& LinkedStack<T>::Add(const T& x)
{
Node<T> *p=new Node<T>;
p->data=x;
p->link=top;
top=p;
return *this;
}
template<class T>
LinkedStack<T>& LinkedStack<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds()";
x=top->data;
Node<T> *p;
p=top->link;
delete top;
top=p;
return *this;
}
int main(void)
{
int x;
LinkedStack<int> S;
try {S.Add(1).Add(2).Add(3).Add(4);}
catch (...) {
cout << "Could not complete additions" << endl;
}
cout << "Stack should be 1234" << endl;
cout << "Stack top is " << S.Top() << endl;
try {
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
S.Delete(x);
cout << "Deleted " << x << endl;
}
catch (...) {
cout << "Last delete failed " << endl;
}
}
(1)括号匹配
View Code #include <iostream>
#include <stack>
#include <string>
using namespace std;
void PrintMatchedPairs(string expr){
stack<int> s;
string::iterator it;
int i=1;
for(it=expr.begin();it!=expr.end();++it,++i){
if(*it=='(')
s.push(i);
else if(*it==')')
{
if(s.empty()){
cout<<"No match for left parentthesis at "<<i<<endl;
}
else{
int t=s.top();
cout<<t<<" "<<i<<endl;
s.pop();
}
}
}
while(!s.empty()) {
int t=s.top();
cout<<"No match for left parentthesis at "<<t<<endl;
s.pop();
}
}
int main(void)
{
const int MaxLength=200;
char expr[MaxLength];
cout << "Type an expression of length at most "
<< MaxLength << endl;
cin.getline(expr, MaxLength);
cout <<"The pairs of matching parentheses in"
<< endl;
cout<<expr<<endl;
cout <<"are" << endl;
string expr2(expr);
PrintMatchedPairs(expr2);
}
#include <stack>
#include <string>
using namespace std;
void PrintMatchedPairs(string expr){
stack<int> s;
string::iterator it;
int i=1;
for(it=expr.begin();it!=expr.end();++it,++i){
if(*it=='(')
s.push(i);
else if(*it==')')
{
if(s.empty()){
cout<<"No match for left parentthesis at "<<i<<endl;
}
else{
int t=s.top();
cout<<t<<" "<<i<<endl;
s.pop();
}
}
}
while(!s.empty()) {
int t=s.top();
cout<<"No match for left parentthesis at "<<t<<endl;
s.pop();
}
}
int main(void)
{
const int MaxLength=200;
char expr[MaxLength];
cout << "Type an expression of length at most "
<< MaxLength << endl;
cin.getline(expr, MaxLength);
cout <<"The pairs of matching parentheses in"
<< endl;
cout<<expr<<endl;
cout <<"are" << endl;
string expr2(expr);
PrintMatchedPairs(expr2);
}
View Code #include <iostream>
#include <stack>
using namespace std;
void TowersofHanoi(int n,int x,int y,int z){
if(n>0){
TowersofHanoi(n-1,x,z,y);
cout<<"move top disk from tower "<<x<<" to top of tower "<<y<<endl;
TowersofHanoi(n-1,z,y,x);
}
}
int main(){
cout << "Moves for a three disk problem are" << endl;
TowersofHanoi(3,1,2,3);
}
#include <stack>
using namespace std;
void TowersofHanoi(int n,int x,int y,int z){
if(n>0){
TowersofHanoi(n-1,x,z,y);
cout<<"move top disk from tower "<<x<<" to top of tower "<<y<<endl;
TowersofHanoi(n-1,z,y,x);
}
}
int main(){
cout << "Moves for a three disk problem are" << endl;
TowersofHanoi(3,1,2,3);
}
网上给出的一个很不错的非递归方式的汉诺塔实现，具体见这，下面是代码：
View Code #include <iostream>
using namespace std;
//圆盘的个数最多为64
const int MAX = 64;
//用来表示每根柱子的信息
struct st{
int s[MAX]; //柱子上的圆盘存储情况
int top; //栈顶，用来最上面的圆盘
char name; //柱子的名字，可以是A，B，C中的一个
int Top()//取栈顶元素
{
return s[top];
}
int Pop()//出栈
{
return s[top--];
}
void Push(int x)//入栈
{
s[++top] = x;
}
} ;
long Pow(int x, int y); //计算x^y
void Creat(st ta[], int n); //给结构数组设置初值
void Hannuota(st ta[], long max); //移动汉诺塔的主要函数
int main(void)
{
int n;
cin >> n; //输入圆盘的个数
st ta[3]; //三根柱子的信息用结构数组存储
Creat(ta, n); //给结构数组设置初值
long max = Pow(2, n) - 1;//动的次数应等于2^n - 1
Hannuota(ta, max);//移动汉诺塔的主要函数
return 0;
}
void Creat(st ta[], int n)
{
ta[0].name = 'A';
ta[0].top = n-1;
//把所有的圆盘按从大到小的顺序放在柱子A上
for (int i=0; i<n; i++)
ta[0].s[i] = n - i;
//柱子B，C上开始没有没有圆盘
ta[1].top = ta[2].top = 0;
for (int i=0; i<n; i++)
ta[1].s[i] = ta[2].s[i] = 0;
//若n为偶数，按顺时针方向依次摆放 A B C
if (n%2 == 0)
{
ta[1].name = 'B';
ta[2].name = 'C';
}
else //若n为奇数，按顺时针方向依次摆放 A C B
{
ta[1].name = 'C';
ta[2].name = 'B';
}
}
long Pow(int x, int y)
{
long sum = 1;
for (int i=0; i<y; i++)
sum *= x;
return sum;
}
void Hannuota(st ta[], long max)
{
int k = 0; //累计移动的次数
int i = 0;
int ch;
while (k < max)
{
//按顺时针方向把圆盘1从现在的柱子移动到下一根柱子
ch = ta[i%3].Pop();
ta[(i+1)%3].Push(ch);
cout << ++k << ": " <<
"Move disk " << ch << " from " << ta[i%3].name <<
" to " << ta[(i+1)%3].name << endl;
i++;
//把另外两根柱子上可以移动的圆盘移动到新的柱子上
if (k < max)
{
//把非空柱子上的圆盘移动到空柱子上，当两根柱子都为空时，移动较小的圆盘
if (ta[(i+1)%3].Top() == 0 ||
ta[(i-1)%3].Top() > 0 &&
ta[(i+1)%3].Top() > ta[(i-1)%3].Top())
{
ch = ta[(i-1)%3].Pop();
ta[(i+1)%3].Push(ch);
cout << ++k << ": " << "Move disk "
<< ch << " from " << ta[(i-1)%3].name
<< " to " << ta[(i+1)%3].name << endl;
}
else
{
ch = ta[(i+1)%3].Pop();
ta[(i-1)%3].Push(ch);
cout << ++k << ": " << "Move disk "
<< ch << " from " << ta[(i+1)%3].name
<< " to " << ta[(i-1)%3].name << endl;
}
}
}
}
using namespace std;
//圆盘的个数最多为64
const int MAX = 64;
//用来表示每根柱子的信息
struct st{
int s[MAX]; //柱子上的圆盘存储情况
int top; //栈顶，用来最上面的圆盘
char name; //柱子的名字，可以是A，B，C中的一个
int Top()//取栈顶元素
{
return s[top];
}
int Pop()//出栈
{
return s[top--];
}
void Push(int x)//入栈
{
s[++top] = x;
}
} ;
long Pow(int x, int y); //计算x^y
void Creat(st ta[], int n); //给结构数组设置初值
void Hannuota(st ta[], long max); //移动汉诺塔的主要函数
int main(void)
{
int n;
cin >> n; //输入圆盘的个数
st ta[3]; //三根柱子的信息用结构数组存储
Creat(ta, n); //给结构数组设置初值
long max = Pow(2, n) - 1;//动的次数应等于2^n - 1
Hannuota(ta, max);//移动汉诺塔的主要函数
return 0;
}
void Creat(st ta[], int n)
{
ta[0].name = 'A';
ta[0].top = n-1;
//把所有的圆盘按从大到小的顺序放在柱子A上
for (int i=0; i<n; i++)
ta[0].s[i] = n - i;
//柱子B，C上开始没有没有圆盘
ta[1].top = ta[2].top = 0;
for (int i=0; i<n; i++)
ta[1].s[i] = ta[2].s[i] = 0;
//若n为偶数，按顺时针方向依次摆放 A B C
if (n%2 == 0)
{
ta[1].name = 'B';
ta[2].name = 'C';
}
else //若n为奇数，按顺时针方向依次摆放 A C B
{
ta[1].name = 'C';
ta[2].name = 'B';
}
}
long Pow(int x, int y)
{
long sum = 1;
for (int i=0; i<y; i++)
sum *= x;
return sum;
}
void Hannuota(st ta[], long max)
{
int k = 0; //累计移动的次数
int i = 0;
int ch;
while (k < max)
{
//按顺时针方向把圆盘1从现在的柱子移动到下一根柱子
ch = ta[i%3].Pop();
ta[(i+1)%3].Push(ch);
cout << ++k << ": " <<
"Move disk " << ch << " from " << ta[i%3].name <<
" to " << ta[(i+1)%3].name << endl;
i++;
//把另外两根柱子上可以移动的圆盘移动到新的柱子上
if (k < max)
{
//把非空柱子上的圆盘移动到空柱子上，当两根柱子都为空时，移动较小的圆盘
if (ta[(i+1)%3].Top() == 0 ||
ta[(i-1)%3].Top() > 0 &&
ta[(i+1)%3].Top() > ta[(i-1)%3].Top())
{
ch = ta[(i-1)%3].Pop();
ta[(i+1)%3].Push(ch);
cout << ++k << ": " << "Move disk "
<< ch << " from " << ta[(i-1)%3].name
<< " to " << ta[(i+1)%3].name << endl;
}
else
{
ch = ta[(i+1)%3].Pop();
ta[(i-1)%3].Push(ch);
cout << ++k << ": " << "Move disk "
<< ch << " from " << ta[(i+1)%3].name
<< " to " << ta[(i-1)%3].name << endl;
}
}
}
}
本人使用STL中的stack对上面的代码进行了一下修改：
View Code class Tower{
public:
stack<int> st;
char name;
};
int Pow(int x,int y){
int sum=1;
for(int i=0;i<y;i++)
sum*=x;
return sum;
}
void Hanoi(int N){
Tower ta[3];
ta[0].name='A';
for(int i=0;i<N;i++)
ta[0].st.push(N-i);
if(N%2==0){
ta[1].name='B';
ta[2].name='C';
}
else{
ta[1].name='C';
ta[2].name='B';
}
int k=0;
int i=0;
int ch;
int max=Pow(2,N)-1;
while(k<max){
ch=ta[i%3].st.top();
ta[i%3].st.pop();
ta[(i+1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[i%3].name<<" to "<<ta[(i+1)%3].name<<endl;
i++;
if(k<max){
if(ta[(i+1)%3].st.empty()||!ta[(i-1)%3].st.empty()&&ta[(i+1)%3].st.top()>ta[(i-1)%3].st.top()){
ch=ta[(i-1)%3].st.top();
ta[(i-1)%3].st.pop();
ta[(i+1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[(i-1)%3].name<<" to "<<ta[(i+1)%3].name<<endl;
}
else{
ch=ta[(i+1)%3].st.top();
ta[(i+1)%3].st.pop();
ta[(i-1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[(i+1)%3].name<<" to "<<ta[(i-1)%3].name<<endl;
}
}
}
}
public:
stack<int> st;
char name;
};
int Pow(int x,int y){
int sum=1;
for(int i=0;i<y;i++)
sum*=x;
return sum;
}
void Hanoi(int N){
Tower ta[3];
ta[0].name='A';
for(int i=0;i<N;i++)
ta[0].st.push(N-i);
if(N%2==0){
ta[1].name='B';
ta[2].name='C';
}
else{
ta[1].name='C';
ta[2].name='B';
}
int k=0;
int i=0;
int ch;
int max=Pow(2,N)-1;
while(k<max){
ch=ta[i%3].st.top();
ta[i%3].st.pop();
ta[(i+1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[i%3].name<<" to "<<ta[(i+1)%3].name<<endl;
i++;
if(k<max){
if(ta[(i+1)%3].st.empty()||!ta[(i-1)%3].st.empty()&&ta[(i+1)%3].st.top()>ta[(i-1)%3].st.top()){
ch=ta[(i-1)%3].st.top();
ta[(i-1)%3].st.pop();
ta[(i+1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[(i-1)%3].name<<" to "<<ta[(i+1)%3].name<<endl;
}
else{
ch=ta[(i+1)%3].st.top();
ta[(i+1)%3].st.pop();
ta[(i-1)%3].st.push(ch);
cout<<++k<<": Move disk "<<ch<<" from "<<ta[(i+1)%3].name<<" to "<<ta[(i-1)%3].name<<endl;
}
}
}
}
下图是对两种方法（递归和迭代）的比较：
（3）火车车厢重排
View Code //using stack
#include <iostream>
#include <vector>
#include <stack>
using namespace std;
bool Hold(int c,int &minH,int& minS,vector<stack<int> >& H,int k,int n){
int BestTrack=0,BestTop=n+1,x;
for(int i=1;i<=k;i++){
if(!H[i].empty()){
x=H[i].top();
if(c<x&&x<BestTop){
BestTop=x;
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
H[BestTrack].push(c);
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
if(c<minH) {
minH=c;
minS=BestTrack;
}
return true;
}
void Output(int& minH,int& minS,vector<stack<int> >& H,int k,int n){
int c;
c=H[minS].top();
H[minS].pop();
cout<<"Move car "<<minH<<" from holding track "<<minS<<" to output"<<endl;
minH=n+2;
for(int i=1;i<=k;i++)
{
if(!H[i].empty()&&(c=H[i].top())<minH){
minH=c;
minS=i;
}
}
}
bool Railroad(int p[],int n,int k){
vector<stack<int> > H(k+1);
int NowOut=1;
int minH=n+1;
int minS;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(minH==NowOut){
Output(minH,minS,H,k,n);
NowOut++;
}
}
else{
if(!Hold(p[i],minH,minS,H,k,n))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
#include <iostream>
#include <vector>
#include <stack>
using namespace std;
bool Hold(int c,int &minH,int& minS,vector<stack<int> >& H,int k,int n){
int BestTrack=0,BestTop=n+1,x;
for(int i=1;i<=k;i++){
if(!H[i].empty()){
x=H[i].top();
if(c<x&&x<BestTop){
BestTop=x;
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
H[BestTrack].push(c);
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
if(c<minH) {
minH=c;
minS=BestTrack;
}
return true;
}
void Output(int& minH,int& minS,vector<stack<int> >& H,int k,int n){
int c;
c=H[minS].top();
H[minS].pop();
cout<<"Move car "<<minH<<" from holding track "<<minS<<" to output"<<endl;
minH=n+2;
for(int i=1;i<=k;i++)
{
if(!H[i].empty()&&(c=H[i].top())<minH){
minH=c;
minS=i;
}
}
}
bool Railroad(int p[],int n,int k){
vector<stack<int> > H(k+1);
int NowOut=1;
int minH=n+1;
int minS;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(minH==NowOut){
Output(minH,minS,H,k,n);
NowOut++;
}
}
else{
if(!Hold(p[i],minH,minS,H,k,n))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
（4）开关盒布线
View Code #include <iostream>
#include <stack>
using namespace std;
bool CheckBox(int net[],int n){
stack<int> s;
for(int i=0;i<n;i++){
if(s.empty()){
s.push(i);
}
else{
if(net[i]==net[s.top()]){
cout<<"Wiring from "<<(i+1)<<" to "<<(s.top()+1)<<endl;
s.pop();
}
else
s.push(i);
}
}
if(s.empty()) {
cout<<"Switch box is routbale"<<endl;
return true;
}
else {
cout<<"Switch box is not routbale";
return false;
}
}
int main(){
int net[]={1,2,2,1,3,3,4,4};
int n=sizeof(net)/sizeof(net[0]);
CheckBox(net,n);
}
#include <stack>
using namespace std;
bool CheckBox(int net[],int n){
stack<int> s;
for(int i=0;i<n;i++){
if(s.empty()){
s.push(i);
}
else{
if(net[i]==net[s.top()]){
cout<<"Wiring from "<<(i+1)<<" to "<<(s.top()+1)<<endl;
s.pop();
}
else
s.push(i);
}
}
if(s.empty()) {
cout<<"Switch box is routbale"<<endl;
return true;
}
else {
cout<<"Switch box is not routbale";
return false;
}
}
int main(){
int net[]={1,2,2,1,3,3,4,4};
int n=sizeof(net)/sizeof(net[0]);
CheckBox(net,n);
}
（5）离线等价类
View Code #include <iostream>
#include <list>
#include <stack>
#include <vector>
using namespace std;
int main(){
int n,r;
cout<<"Enter number of elements"<<endl;
cin>>n;
if(n<2){
cerr<<"Too few elements"<<endl;
return 1;
}
cout<<"Enter number of relations"<<endl;
cin>>r;
if(r<1){
cerr<<"Too few relations"<<endl;
return 1;
}
vector<list<int> > chain(n+1);
for(int i=1;i<=r;i++)
{
cout<<"Enter next relation/pair"<<endl;
int a,b;
cin>>a>>b;
chain[a].push_front(b);
chain[b].push_front(a);
}
stack<int> s;
vector<bool> out(n+1);
for(int i=1;i<=n;i++)
out[i]=false;
for(int i=1;i<=n;i++){
if(!out[i]){
cout<<"Next class is:"<<i<<' ';
out[i]=true;
s.push(i);
list<int>::const_iterator it;
while(!s.empty()){
int j=s.top();
s.pop();
for(it=chain[j].begin();it!=chain[j].end();++it)
if(!out[*it]){
cout<<*it<<' ';
out[*it]=true;
s.push(*it);
}
}
cout<<endl;
}
}
}
#include <list>
#include <stack>
#include <vector>
using namespace std;
int main(){
int n,r;
cout<<"Enter number of elements"<<endl;
cin>>n;
if(n<2){
cerr<<"Too few elements"<<endl;
return 1;
}
cout<<"Enter number of relations"<<endl;
cin>>r;
if(r<1){
cerr<<"Too few relations"<<endl;
return 1;
}
vector<list<int> > chain(n+1);
for(int i=1;i<=r;i++)
{
cout<<"Enter next relation/pair"<<endl;
int a,b;
cin>>a>>b;
chain[a].push_front(b);
chain[b].push_front(a);
}
stack<int> s;
vector<bool> out(n+1);
for(int i=1;i<=n;i++)
out[i]=false;
for(int i=1;i<=n;i++){
if(!out[i]){
cout<<"Next class is:"<<i<<' ';
out[i]=true;
s.push(i);
list<int>::const_iterator it;
while(!s.empty()){
int j=s.top();
s.pop();
for(it=chain[j].begin();it!=chain[j].end();++it)
if(!out[*it]){
cout<<*it<<' ';
out[*it]=true;
s.push(*it);
}
}
cout<<endl;
}
}
}
（6）迷宫老鼠
View Code #include <iostream>
#include <fstream>
#include <stack>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(Position& a,Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
int **maze,m;
bool **flag;
stack<Position> path;
const char *const red = "\033[0;40;31m";
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &maze,int w,int h){
maze=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
maze[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
bool InputMaze(const char *file)
{// Input the maze.
ifstream inf(file);
inf >> m;
cout << " maze size: "<<m<< endl;
make2darray(maze, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> maze[i][j];
cout << "the maze:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< maze[i][j]<<" ";
cout<<endl;
}
cout<<endl;
make2darray(flag, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
flag[i][j]=false;
return true;
}
void OutputPath()
{// Output path to exit.
cout << "The path is" << endl;
Position here;
while (!path.empty()) {
here=path.top();
path.pop();
cout << here.x << ' ' << here.y << endl;
flag[here.x][here.y]=true;
}
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(flag[i][j])
printf("%s%d%s ",red,maze[i][j],normal);
else
printf("%d ",maze[i][j]);
}
printf("\n");
}
printf("\n");
}
bool FindPath(){
Position here={0,0};
Position offset[4]={{0,1},{1,0},{0,-1},{-1,0}};
maze[0][0]=1;
int i=0;
while(here.x!=m-1||here.y!=m-1){
Position location;
int lx,ly;
while(i<4){
location=here+offset[i];
lx=location.x;
ly=location.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(maze[lx][ly]==0)
break;
}
i++;
}
if(i<4){
path.push(here);
here=location;
maze[lx][ly]=1;
i=0;
}
else{
if(path.empty())
return false;
Position next;
next=path.top();
path.pop();
if(next.x==here.x)
i=2+next.y-here.y;
else
i=3+next.x-here.x;
here=next;
}
}
path.push(here);
return true;
}
int main(){
InputMaze("maze.dat");
if (FindPath()) OutputPath();
else cout << "No path" << endl;
free2darray(maze);
free2darray(flag);
}
#include <fstream>
#include <stack>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(Position& a,Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
int **maze,m;
bool **flag;
stack<Position> path;
const char *const red = "\033[0;40;31m";
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &maze,int w,int h){
maze=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
maze[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
bool InputMaze(const char *file)
{// Input the maze.
ifstream inf(file);
inf >> m;
cout << " maze size: "<<m<< endl;
make2darray(maze, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> maze[i][j];
cout << "the maze:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< maze[i][j]<<" ";
cout<<endl;
}
cout<<endl;
make2darray(flag, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
flag[i][j]=false;
return true;
}
void OutputPath()
{// Output path to exit.
cout << "The path is" << endl;
Position here;
while (!path.empty()) {
here=path.top();
path.pop();
cout << here.x << ' ' << here.y << endl;
flag[here.x][here.y]=true;
}
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(flag[i][j])
printf("%s%d%s ",red,maze[i][j],normal);
else
printf("%d ",maze[i][j]);
}
printf("\n");
}
printf("\n");
}
bool FindPath(){
Position here={0,0};
Position offset[4]={{0,1},{1,0},{0,-1},{-1,0}};
maze[0][0]=1;
int i=0;
while(here.x!=m-1||here.y!=m-1){
Position location;
int lx,ly;
while(i<4){
location=here+offset[i];
lx=location.x;
ly=location.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(maze[lx][ly]==0)
break;
}
i++;
}
if(i<4){
path.push(here);
here=location;
maze[lx][ly]=1;
i=0;
}
else{
if(path.empty())
return false;
Position next;
next=path.top();
path.pop();
if(next.x==here.x)
i=2+next.y-here.y;
else
i=3+next.x-here.x;
here=next;
}
}
path.push(here);
return true;
}
int main(){
InputMaze("maze.dat");
if (FindPath()) OutputPath();
else cout << "No path" << endl;
free2darray(maze);
free2darray(flag);
}
迷宫数据：
10
0 1 1 1 1 1 0 0 0 0
0 0 0 0 0 1 0 1 0 0
0 0 0 1 0 1 0 0 0 0
0 1 0 1 0 1 0 1 1 0
0 1 0 1 0 1 0 1 0 0
0 1 1 1 0 1 0 1 0 1
0 1 0 0 0 1 0 1 0 1
0 1 0 1 1 1 0 1 0 0
1 0 0 0 0 0 0 1 0 0
0 0 0 0 1 1 1 1 0 0
程序输出如下：
第6章 队列
队列是一个先进先出( first-in-first-out, FIFO)的线性表
1. 公式化实现队列
实现代码：
View Code #include <iostream>
using namespace std;
template <class T>
class Queue{
public:
Queue(int Size=10);
~Queue(){
delete [] queue;
}
bool IsEmpty()const{
return front==rear;
}
bool IsFull()const{
return ((rear+1)%MaxSize==front)?true:false;
}
T First()const;
T Last()const;
Queue<T>& Add(const T& x);
Queue<T>& Delete(T& x);
private:
int front;
int rear;
int MaxSize;
T *queue;
};
template <class T>
Queue<T>::Queue(int size)
{
MaxSize=size;
queue=new T[size];
front=rear=0;
}
template <class T>
T Queue<T>::First()const
{
if(IsEmpty())
throw "Out of Bounds";
return queue[(front+1)%MaxSize];
}
template <class T>
T Queue<T>::Last()const
{
if(IsEmpty())
throw "Out of Bounds";
return queue[rear];
}
template <class T>
Queue<T>& Queue<T>::Add(const T& x)
{
if(IsFull())
throw "No memorry";
rear=(rear+1)%MaxSize;
queue[rear]=x;
return *this;
}
template <class T>
Queue<T>& Queue<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds";
front=(front+1)%MaxSize;
x=queue[front];
return *this;
}
int main(void)
{
Queue<int> Q(3);
int x;
try {Q.Add(1).Add(2).Add(3).Add(4);
cout << "No queue add failed" << endl;}
catch (...)
{cout << "A queue add failed" << endl;}
cout << "Queue is now 123" << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << Q.First() << " is at front" << endl;
cout << Q.Last() << " is at end" << endl;
try {
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << "No queue delete failed " << endl;
}
catch (...)
{cout << "A delete has failed" << endl;}
}
using namespace std;
template <class T>
class Queue{
public:
Queue(int Size=10);
~Queue(){
delete [] queue;
}
bool IsEmpty()const{
return front==rear;
}
bool IsFull()const{
return ((rear+1)%MaxSize==front)?true:false;
}
T First()const;
T Last()const;
Queue<T>& Add(const T& x);
Queue<T>& Delete(T& x);
private:
int front;
int rear;
int MaxSize;
T *queue;
};
template <class T>
Queue<T>::Queue(int size)
{
MaxSize=size;
queue=new T[size];
front=rear=0;
}
template <class T>
T Queue<T>::First()const
{
if(IsEmpty())
throw "Out of Bounds";
return queue[(front+1)%MaxSize];
}
template <class T>
T Queue<T>::Last()const
{
if(IsEmpty())
throw "Out of Bounds";
return queue[rear];
}
template <class T>
Queue<T>& Queue<T>::Add(const T& x)
{
if(IsFull())
throw "No memorry";
rear=(rear+1)%MaxSize;
queue[rear]=x;
return *this;
}
template <class T>
Queue<T>& Queue<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds";
front=(front+1)%MaxSize;
x=queue[front];
return *this;
}
int main(void)
{
Queue<int> Q(3);
int x;
try {Q.Add(1).Add(2).Add(3).Add(4);
cout << "No queue add failed" << endl;}
catch (...)
{cout << "A queue add failed" << endl;}
cout << "Queue is now 123" << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << Q.First() << " is at front" << endl;
cout << Q.Last() << " is at end" << endl;
try {
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << "No queue delete failed " << endl;
}
catch (...)
{cout << "A delete has failed" << endl;}
}
2. 链表描述
实现代码：
View Code #include <iostream>
using namespace std;
template <class T>
class LinkedQueue;
template <class T>
class Node{
friend class LinkedQueue<T>;
private:
T data;
Node<T> *link;
};
template <class T>
class LinkedQueue{
public:
LinkedQueue(){
front=rear=0;
}
~LinkedQueue();
bool IsEmpty()const{
return (front)?false:true;
}
bool IsFull()const;
T First()const;
T Last()const;
LinkedQueue<T>& Add(const T& x);
LinkedQueue<T>& Delete(T& x);
private:
Node<T>*front;
Node<T>*rear;
};
template <class T>
LinkedQueue<T>::~LinkedQueue()
{
Node<T>*next;
while(front){
next=front->link;
delete front;
front=next;
}
}
template <class T>
bool LinkedQueue<T>::IsFull()const
{
Node<T>*p;
try{
p=new Node<T>;
delete p;
return false;
}
catch(...){
return true;
}
}
template <class T>
T LinkedQueue<T>::First()const
{
if(IsEmpty())
throw "Out of Bounds";
return front->data;
}
template <class T>
T LinkedQueue<T>::Last()const
{
if(IsEmpty())
throw "Out of Bounds";
return rear->data;
}
template <class T>
LinkedQueue<T>& LinkedQueue<T>::Add(const T& x)
{
Node<T>*p=new Node<T>;
p->data=x;
p->link=0;
if(front) rear->link=p;
else
front=p;
rear=p;
return *this;
}
template <class T>
LinkedQueue<T>& LinkedQueue<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds";
x=front->data;
Node<T>*p;
p=front->link;
delete front;
front=p;
return *this;
}
int main(void)
{
LinkedQueue<int> Q;
int x;
try {Q.Add(1).Add(2).Add(3).Add(4);
cout << "No queue add failed" << endl;}
catch (...)
{cout << "A queue add failed" << endl;}
cout << "Queue is now 1234" << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << Q.First() << " is at front" << endl;
cout << Q.Last() << " is at end" << endl;
try {
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << "No queue delete failed " << endl;
}
catch (...)
{cout << "A delete has failed" << endl;}
}
using namespace std;
template <class T>
class LinkedQueue;
template <class T>
class Node{
friend class LinkedQueue<T>;
private:
T data;
Node<T> *link;
};
template <class T>
class LinkedQueue{
public:
LinkedQueue(){
front=rear=0;
}
~LinkedQueue();
bool IsEmpty()const{
return (front)?false:true;
}
bool IsFull()const;
T First()const;
T Last()const;
LinkedQueue<T>& Add(const T& x);
LinkedQueue<T>& Delete(T& x);
private:
Node<T>*front;
Node<T>*rear;
};
template <class T>
LinkedQueue<T>::~LinkedQueue()
{
Node<T>*next;
while(front){
next=front->link;
delete front;
front=next;
}
}
template <class T>
bool LinkedQueue<T>::IsFull()const
{
Node<T>*p;
try{
p=new Node<T>;
delete p;
return false;
}
catch(...){
return true;
}
}
template <class T>
T LinkedQueue<T>::First()const
{
if(IsEmpty())
throw "Out of Bounds";
return front->data;
}
template <class T>
T LinkedQueue<T>::Last()const
{
if(IsEmpty())
throw "Out of Bounds";
return rear->data;
}
template <class T>
LinkedQueue<T>& LinkedQueue<T>::Add(const T& x)
{
Node<T>*p=new Node<T>;
p->data=x;
p->link=0;
if(front) rear->link=p;
else
front=p;
rear=p;
return *this;
}
template <class T>
LinkedQueue<T>& LinkedQueue<T>::Delete(T& x)
{
if(IsEmpty())
throw "Out of Bounds";
x=front->data;
Node<T>*p;
p=front->link;
delete front;
front=p;
return *this;
}
int main(void)
{
LinkedQueue<int> Q;
int x;
try {Q.Add(1).Add(2).Add(3).Add(4);
cout << "No queue add failed" << endl;}
catch (...)
{cout << "A queue add failed" << endl;}
cout << "Queue is now 1234" << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << Q.First() << " is at front" << endl;
cout << Q.Last() << " is at end" << endl;
try {
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
Q.Delete(x);
cout << "Deleted " << x << endl;
cout << "No queue delete failed " << endl;
}
catch (...)
{cout << "A delete has failed" << endl;}
}
3. 队列的应用
（1）火车重排
View Code //using queue
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
bool Hold(int c,int &minH,int& minQ,vector<queue<int> >& H,int k){
int BestTrack=0,BestLast=0,x;
for(int i=1;i<=k;i++){
if(!H[i].empty()){
x=H[i].back();
if(c>x&&x>BestLast){
BestLast=x;
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
H[BestTrack].push(c);
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
if(c<minH) {
minH=c;
minQ=BestTrack;
}
return true;
}
void Output(int& minH,int& minQ,vector<queue<int> >& H,int k,int n){
int c;
c=H[minQ].front();
H[minQ].pop();
cout<<"Move car "<<minH<<" from holding track "<<minQ<<" to output"<<endl;
minH=n+2;
for(int i=1;i<=k;i++)
{
if(!H[i].empty()&&(c=H[i].front())<minH){
minH=c;
minQ=i;
}
}
}
bool Railroad(int p[],int n,int k){
vector<queue<int> > H(k);
k--;
int NowOut=1;
int minH=n+1;
int minQ;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(minH==NowOut){
Output(minH,minQ,H,k,n);
NowOut++;
}
}
else{
if(!Hold(p[i],minH,minQ,H,k))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
bool Hold(int c,int &minH,int& minQ,vector<queue<int> >& H,int k){
int BestTrack=0,BestLast=0,x;
for(int i=1;i<=k;i++){
if(!H[i].empty()){
x=H[i].back();
if(c>x&&x>BestLast){
BestLast=x;
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
H[BestTrack].push(c);
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
if(c<minH) {
minH=c;
minQ=BestTrack;
}
return true;
}
void Output(int& minH,int& minQ,vector<queue<int> >& H,int k,int n){
int c;
c=H[minQ].front();
H[minQ].pop();
cout<<"Move car "<<minH<<" from holding track "<<minQ<<" to output"<<endl;
minH=n+2;
for(int i=1;i<=k;i++)
{
if(!H[i].empty()&&(c=H[i].front())<minH){
minH=c;
minQ=i;
}
}
}
bool Railroad(int p[],int n,int k){
vector<queue<int> > H(k);
k--;
int NowOut=1;
int minH=n+1;
int minQ;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(minH==NowOut){
Output(minH,minQ,H,k,n);
NowOut++;
}
}
else{
if(!Hold(p[i],minH,minQ,H,k))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
不使用队列的实现：
View Code //with LIFO tracks
//no explicted queue used
#include <iostream>
#include <vector>
using namespace std;
bool Hold(int c,vector<int>& last,vector<int>& track,int k){
int BestTrack=0,BestLast=0;
for(int i=1;i<=k;i++){
if(last[i]){
if(c>last[i]&&last[i]>BestLast){
BestLast=last[i];
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
track[c]=BestTrack;
last[BestTrack]=c;
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
return true;
}
void Output(int NowOut,int Track,int& Last){
cout<<"Move car "<<NowOut<<" from holding track "<<Track<<" to output"<<endl;
if(NowOut==Last)
Last=0;
}
bool Railroad(int p[],int n,int k){
vector<int> last(k+1);
vector<int> track(n+1);
for(int i=1;i<=k;i++)
last[i]=0;
for(int i=1;i<=n;i++)
track[i]=0;
k--;
int NowOut=1;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(NowOut<=n&&track[NowOut]){
Output(NowOut,track[NowOut],last[NowOut]);
NowOut++;
}
}
else{
if(!Hold(p[i],last,track,k))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
//no explicted queue used
#include <iostream>
#include <vector>
using namespace std;
bool Hold(int c,vector<int>& last,vector<int>& track,int k){
int BestTrack=0,BestLast=0;
for(int i=1;i<=k;i++){
if(last[i]){
if(c>last[i]&&last[i]>BestLast){
BestLast=last[i];
BestTrack=i;
}
}
else{
if(!BestTrack)
BestTrack=i;
}
}
if(!BestTrack)
return false;
track[c]=BestTrack;
last[BestTrack]=c;
cout<<"Move car "<<c<<" from input to holding track "<<BestTrack<<endl;
return true;
}
void Output(int NowOut,int Track,int& Last){
cout<<"Move car "<<NowOut<<" from holding track "<<Track<<" to output"<<endl;
if(NowOut==Last)
Last=0;
}
bool Railroad(int p[],int n,int k){
vector<int> last(k+1);
vector<int> track(n+1);
for(int i=1;i<=k;i++)
last[i]=0;
for(int i=1;i<=n;i++)
track[i]=0;
k--;
int NowOut=1;
for(int i=1;i<=n;i++){
if(p[i]==NowOut){
cout<<"Move car "<<p[i]<<" from input to output"<<endl;
NowOut++;
while(NowOut<=n&&track[NowOut]){
Output(NowOut,track[NowOut],last[NowOut]);
NowOut++;
}
}
else{
if(!Hold(p[i],last,track,k))
return false;
}
}
return true;
}
int main(){
int p[10] = {0, 3, 6, 9, 2, 4, 7, 1, 8, 5};
cout << "Input permutation is 0369247185" << endl;
Railroad(p,9,3);
}
（2）电路布线
View Code #include <iostream>
#include <fstream>
#include <queue>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(const Position& a,const Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
bool operator==(const Position& a,const Position& b){
return (a.x==b.x&&a.y==b.y);
}
Position operator-(const Position& a,int t){
Position temp;
temp.x=a.x-t;
temp.y=a.y-t;
return temp;
}
Position operator+(const Position& a,int t){
Position temp;
temp.x=a.x+t;
temp.y=a.y+t;
return temp;
}
istream& operator>>(istream& is,Position& ps){
is>>ps.x>>ps.y;
return is;
}
ostream& operator<<(ostream& os,const Position& ps){
os<<"("<<ps.x<<","<<ps.y<<")";
return os;
}
int **grid,m;
bool **flag;
const char *const red = "\033[0;40;31m";
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &grid,int w,int h){
grid=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
grid[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
bool Inputgrid(const char *file,Position& start,Position& finish)
{// Input the grid.
ifstream inf(file);
inf >> m;
cout << " grid size: "<<m<< endl;
make2darray(grid, m, m);
inf>>start;
inf>>finish;
start=start-1;
finish=finish-1;
cout<<"start:"<<start<<endl;
cout<<"finish:"<<finish<<endl;
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> grid[i][j];
cout << "the grid:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< grid[i][j]<<" ";
cout<<endl;
}
cout<<endl;
make2darray(flag, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
flag[i][j]=false;
return true;
}
void OutputPath(vector<Position>& path)
{// Output path to exit.
cout << "The path is" << endl;
vector<Position>::const_iterator it;
for(it=path.begin();it!=path.end();++it){
cout<<*it<<endl;
flag[it->x][it->y]=true;
}
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(flag[i][j])
printf("%s%d%s ",red,grid[i][j],normal);
else
printf("%d ",grid[i][j]);
}
printf("\n");
}
printf("\n");
}
bool FindPath(const Position& start,const Position& finish,vector<Position>& path){
// if((start.x==finish.x)&&(start.y==finish.y)){
if((start==finish)){
return true;
}
Position here=start;
Position nbr;
const int NumOfNbrs=4;
Position offset[]={{0,1},{1,0},{0,-1},{-1,0}};
grid[start.x][start.y]=2;
queue<Position> Q;
int lx,ly;
do{
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(grid[nbr.x][nbr.y]==0){
grid[nbr.x][nbr.y]=grid[here.x][here.y]+1;
if(nbr==finish)
break;
Q.push(nbr);
}
}
}
if(nbr==finish)
break;
if(Q.empty())
return false;
here=Q.front();
Q.pop();
}while(1);
int PathLen=grid[finish.x][finish.y]-2;
path.resize(PathLen);
here=finish;
for(int j=PathLen-1;j>=0;j--){
path[j]=here;
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(grid[nbr.x][nbr.y]==j+2)
break;
}
}
here=nbr;
}
return true;
}
int main(){
Position start,finish;
Inputgrid("wire.dat",start,finish);
vector<Position> path;
if (FindPath(start,finish,path))
OutputPath(path);
else
cout << "No path" << endl;
free2darray(grid);
free2darray(flag);
}
#include <fstream>
#include <queue>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(const Position& a,const Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
bool operator==(const Position& a,const Position& b){
return (a.x==b.x&&a.y==b.y);
}
Position operator-(const Position& a,int t){
Position temp;
temp.x=a.x-t;
temp.y=a.y-t;
return temp;
}
Position operator+(const Position& a,int t){
Position temp;
temp.x=a.x+t;
temp.y=a.y+t;
return temp;
}
istream& operator>>(istream& is,Position& ps){
is>>ps.x>>ps.y;
return is;
}
ostream& operator<<(ostream& os,const Position& ps){
os<<"("<<ps.x<<","<<ps.y<<")";
return os;
}
int **grid,m;
bool **flag;
const char *const red = "\033[0;40;31m";
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &grid,int w,int h){
grid=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
grid[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
bool Inputgrid(const char *file,Position& start,Position& finish)
{// Input the grid.
ifstream inf(file);
inf >> m;
cout << " grid size: "<<m<< endl;
make2darray(grid, m, m);
inf>>start;
inf>>finish;
start=start-1;
finish=finish-1;
cout<<"start:"<<start<<endl;
cout<<"finish:"<<finish<<endl;
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> grid[i][j];
cout << "the grid:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< grid[i][j]<<" ";
cout<<endl;
}
cout<<endl;
make2darray(flag, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
flag[i][j]=false;
return true;
}
void OutputPath(vector<Position>& path)
{// Output path to exit.
cout << "The path is" << endl;
vector<Position>::const_iterator it;
for(it=path.begin();it!=path.end();++it){
cout<<*it<<endl;
flag[it->x][it->y]=true;
}
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(flag[i][j])
printf("%s%d%s ",red,grid[i][j],normal);
else
printf("%d ",grid[i][j]);
}
printf("\n");
}
printf("\n");
}
bool FindPath(const Position& start,const Position& finish,vector<Position>& path){
// if((start.x==finish.x)&&(start.y==finish.y)){
if((start==finish)){
return true;
}
Position here=start;
Position nbr;
const int NumOfNbrs=4;
Position offset[]={{0,1},{1,0},{0,-1},{-1,0}};
grid[start.x][start.y]=2;
queue<Position> Q;
int lx,ly;
do{
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(grid[nbr.x][nbr.y]==0){
grid[nbr.x][nbr.y]=grid[here.x][here.y]+1;
if(nbr==finish)
break;
Q.push(nbr);
}
}
}
if(nbr==finish)
break;
if(Q.empty())
return false;
here=Q.front();
Q.pop();
}while(1);
int PathLen=grid[finish.x][finish.y]-2;
path.resize(PathLen);
here=finish;
for(int j=PathLen-1;j>=0;j--){
path[j]=here;
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(grid[nbr.x][nbr.y]==j+2)
break;
}
}
here=nbr;
}
return true;
}
int main(){
Position start,finish;
Inputgrid("wire.dat",start,finish);
vector<Position> path;
if (FindPath(start,finish,path))
OutputPath(path);
else
cout << "No path" << endl;
free2darray(grid);
free2darray(flag);
}
布线路图：
7
3 2
4 6
0 0 1 0 0 0 0
0 0 1 1 0 0 0
0 0 0 0 1 0 0
0 0 0 1 1 0 0
1 0 0 0 1 0 0
1 1 1 0 0 0 0
1 1 1 0 0 0 0
程序输出如下：
（3）识别图元
View Code #include <iostream>
#include <fstream>
#include <queue>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(const Position& a,const Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
int **pixel,m;
const char *color[]={ "\033[0;40;31m","\033[0;40;32m","\033[0;40;33m","\033[0;40;34m","\033[0;40;35m","\033[0;40;36m"};
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &pixel,int w,int h){
pixel=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
pixel[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
void InputImage(const char*file)
{// Input the pixel.
ifstream inf(file);
inf >> m;
cout << " pixel size: "<<m<< endl;
make2darray(pixel, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> pixel[i][j];
cout << "the pixel:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< pixel[i][j];
cout<<endl;
}
cout<<endl;
}
void OutputImage()
{// Output path to exit.
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(pixel[i][j]>1)
printf("%s%d%s ",color[pixel[i][j]-2],pixel[i][j],normal);
else
printf("%d ",pixel[i][j]);
}
printf("\n");
}
printf("\n");
}
void Label(){
const int NumOfNbrs=4;
Position offset[]={{0,1},{1,0},{0,-1},{-1,0}};
Position here,nbr;
queue<Position> Q;
int id=1;
for(int r=0;r<m;r++){
for(int c=0;c<m;c++){
if(pixel[r][c]==1){
pixel[r][c]=++id;
here.x=r;
here.y=c;
int lx,ly;
do{
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(pixel[lx][ly]==1){
pixel[lx][ly]=id;
Q.push(nbr);
}
}
}
if(Q.empty())
break;
here=Q.front();
Q.pop();
}while(1);
}
}
}
}
int main(){
const char*file="image.dat";
InputImage(file);
cout << "The input image is" << endl;
OutputImage();
Label();
cout << "The labeled image is" << endl;
OutputImage();
}
#include <fstream>
#include <queue>
#include <cstdio>
using namespace std;
struct Position{
int x;
int y;
};
Position operator+(const Position& a,const Position& b){
Position p;
p.x=a.x+b.x;
p.y=a.y+b.y;
return p;
}
int **pixel,m;
const char *color[]={ "\033[0;40;31m","\033[0;40;32m","\033[0;40;33m","\033[0;40;34m","\033[0;40;35m","\033[0;40;36m"};
const char *const normal = "\033[0m";
template <class T>
void make2darray(T ** &pixel,int w,int h){
pixel=new T*[w];
T *mem=new T[w*h];
for(int i=0;i<w;i++)
pixel[i]=mem+i*h;
}
template <class T>
void free2darray(T** maze){
if(maze){
if(*maze)
delete[] *maze;
delete[] maze;
}
}
void InputImage(const char*file)
{// Input the pixel.
ifstream inf(file);
inf >> m;
cout << " pixel size: "<<m<< endl;
make2darray(pixel, m, m);
for (int i=0; i<m; i++)
for (int j=0; j<m; j++)
inf >> pixel[i][j];
cout << "the pixel:" << endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
cout<< pixel[i][j];
cout<<endl;
}
cout<<endl;
}
void OutputImage()
{// Output path to exit.
cout<<"Another:"<<endl;
for (int i=0; i<m; i++) {
for (int j=0; j<m; j++)
{
if(pixel[i][j]>1)
printf("%s%d%s ",color[pixel[i][j]-2],pixel[i][j],normal);
else
printf("%d ",pixel[i][j]);
}
printf("\n");
}
printf("\n");
}
void Label(){
const int NumOfNbrs=4;
Position offset[]={{0,1},{1,0},{0,-1},{-1,0}};
Position here,nbr;
queue<Position> Q;
int id=1;
for(int r=0;r<m;r++){
for(int c=0;c<m;c++){
if(pixel[r][c]==1){
pixel[r][c]=++id;
here.x=r;
here.y=c;
int lx,ly;
do{
for(int i=0;i<NumOfNbrs;i++){
nbr=here+offset[i];
lx=nbr.x;
ly=nbr.y;
if(!(lx<0||ly<0||lx>m-1||ly>m-1)){
if(pixel[lx][ly]==1){
pixel[lx][ly]=id;
Q.push(nbr);
}
}
}
if(Q.empty())
break;
here=Q.front();
Q.pop();
}while(1);
}
}
}
}
int main(){
const char*file="image.dat";
InputImage(file);
cout << "The input image is" << endl;
OutputImage();
Label();
cout << "The labeled image is" << endl;
OutputImage();
}
图元数据：
7
0 0 1 0 0 0 0
0 0 1 1 0 0 0
0 0 0 0 1 0 0
0 0 0 1 1 0 0
1 0 0 0 1 0 0
1 1 1 0 0 0 0
1 1 1 0 0 0 0
0 0 1 0 0 0 0
0 0 1 1 0 0 0
0 0 0 0 1 0 0
0 0 0 1 1 0 0
1 0 0 0 1 0 0
1 1 1 0 0 0 0
1 1 1 0 0 0 0
程序输出：
第7章 跳表和散列
1. 线性表来实现字典，该线性表按关键字从左到右依次增大。
View Code 2. 跳表描述
（1）理想情况
（2）插入删除
（3）级的分配
（4）复杂性
View Code 3. 散列表描述/哈希表
（1）线性开型寻址
1. 线性表来实现字典，该线性表按关键字从左到右依次增大。
View Code #include <iostream>
using namespace std;
template <class E, class K> class SortedChain;
template <class E, class K>
class SortedChainNode {
friend class SortedChain<E,K>;
private:
E data;
K key;
SortedChainNode<E,K> *link;
};
template<class E,class K>
class SortedChain{
public:
SortedChain(){
first=0;
}
~SortedChain();
bool IsEmpty()const{
return first==0;
}
int Length()const;
bool Search(const K& k,E& e)const;
SortedChain<E,K>& Delete(const K& k,E& e);
SortedChain<E,K>& Insert(const K& k,const E& e);
SortedChain<E,K>& DistinctInsert(const K&k,const E& e);
void Output(ostream& out) const;
private:
SortedChainNode<E,K> *first;
};
template<class E,class K>
SortedChain<E,K>::~SortedChain()
{
SortedChainNode<E,K>* next;
while(first){
next=first->link;
delete first;
first=next;
}
}
template<class E,class K>
int SortedChain<E,K>::Length()const
{
SortedChainNode<E,K>* p=first;
int len=0;
while(p){
p=p->link;
len++;
}
return len;
}
template<class E,class K>
bool SortedChain<E,K>::Search(const K& k,E& e)const
{
SortedChainNode<E,K> *p=first;
while(p&&p->key<k)
p=p->link;
if(p&&p->key==k) {
e=p->data;
return true;
}
return false;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::Delete(const K& k,E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
if(p&&p->key==k){
e=p->data;
if(tp)
tp->link=p->link;
else
first=p->link;
delete p;
return *this;
}
throw "Bad Input";
return *this;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::Insert(const K& k,const E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
SortedChainNode<E,K> *q=new SortedChainNode<E,K>;
q->key=k;
q->data=e;
q->link=p;
if(tp)
tp->link=q;
else
first=q;
return *this;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::DistinctInsert(const K& k,const E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
if(p&&p->data==e)
throw "Bad Input";
SortedChainNode<E,K> *q=new SortedChainNode<E,K>;
q->key=k;
q->data=e;
q->link=p;
if(tp)
tp->link=q;
else
first=q;
return *this;
}
template<class E,class K>
void SortedChain<E,K>::Output(ostream& out) const
{
SortedChainNode<E,K>*p;
p=first;
while(p){
out<<"("<<p->key<<","<<p->data<<") ";
p=p->link;
}
}
template<class E,class K>
ostream& operator<<(ostream& out,const SortedChain<E,K>& x){
x.Output(out);
return out;
}
int main(void)
{
SortedChain<int, int> Z;
int x;
Z.Insert(2,2).Insert(6,6).Insert(4,4);
cout << "The chain is " << Z << endl;
cout << "Its length is " << Z.Length() << endl;
Z.Delete(2,x);
cout << "Deleted " << x << endl;
cout << Z << endl;
Z.Insert(1,1).Delete(6,x);
cout << Z << endl;
Z.Insert(8,8).Insert(9,9).Search(8,x);
cout << "Found " << x << endl;
Z.Insert(7,7).Delete(9,x);
cout << Z << endl;
try {Z.DistinctInsert(7,7);}
catch (...)
{cout << "Attempt to insert duplicate element" << endl;}
cout << Z << endl;
Z.DistinctInsert(10,10);
cout << Z << endl;
}
using namespace std;
template <class E, class K> class SortedChain;
template <class E, class K>
class SortedChainNode {
friend class SortedChain<E,K>;
private:
E data;
K key;
SortedChainNode<E,K> *link;
};
template<class E,class K>
class SortedChain{
public:
SortedChain(){
first=0;
}
~SortedChain();
bool IsEmpty()const{
return first==0;
}
int Length()const;
bool Search(const K& k,E& e)const;
SortedChain<E,K>& Delete(const K& k,E& e);
SortedChain<E,K>& Insert(const K& k,const E& e);
SortedChain<E,K>& DistinctInsert(const K&k,const E& e);
void Output(ostream& out) const;
private:
SortedChainNode<E,K> *first;
};
template<class E,class K>
SortedChain<E,K>::~SortedChain()
{
SortedChainNode<E,K>* next;
while(first){
next=first->link;
delete first;
first=next;
}
}
template<class E,class K>
int SortedChain<E,K>::Length()const
{
SortedChainNode<E,K>* p=first;
int len=0;
while(p){
p=p->link;
len++;
}
return len;
}
template<class E,class K>
bool SortedChain<E,K>::Search(const K& k,E& e)const
{
SortedChainNode<E,K> *p=first;
while(p&&p->key<k)
p=p->link;
if(p&&p->key==k) {
e=p->data;
return true;
}
return false;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::Delete(const K& k,E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
if(p&&p->key==k){
e=p->data;
if(tp)
tp->link=p->link;
else
first=p->link;
delete p;
return *this;
}
throw "Bad Input";
return *this;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::Insert(const K& k,const E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
SortedChainNode<E,K> *q=new SortedChainNode<E,K>;
q->key=k;
q->data=e;
q->link=p;
if(tp)
tp->link=q;
else
first=q;
return *this;
}
template<class E,class K>
SortedChain<E,K>& SortedChain<E,K>::DistinctInsert(const K& k,const E& e)
{
SortedChainNode<E,K>*p=first,*tp=0;
while(p&&p->key<k){
tp=p;
p=p->link;
}
if(p&&p->data==e)
throw "Bad Input";
SortedChainNode<E,K> *q=new SortedChainNode<E,K>;
q->key=k;
q->data=e;
q->link=p;
if(tp)
tp->link=q;
else
first=q;
return *this;
}
template<class E,class K>
void SortedChain<E,K>::Output(ostream& out) const
{
SortedChainNode<E,K>*p;
p=first;
while(p){
out<<"("<<p->key<<","<<p->data<<") ";
p=p->link;
}
}
template<class E,class K>
ostream& operator<<(ostream& out,const SortedChain<E,K>& x){
x.Output(out);
return out;
}
int main(void)
{
SortedChain<int, int> Z;
int x;
Z.Insert(2,2).Insert(6,6).Insert(4,4);
cout << "The chain is " << Z << endl;
cout << "Its length is " << Z.Length() << endl;
Z.Delete(2,x);
cout << "Deleted " << x << endl;
cout << Z << endl;
Z.Insert(1,1).Delete(6,x);
cout << Z << endl;
Z.Insert(8,8).Insert(9,9).Search(8,x);
cout << "Found " << x << endl;
Z.Insert(7,7).Delete(9,x);
cout << Z << endl;
try {Z.DistinctInsert(7,7);}
catch (...)
{cout << "Attempt to insert duplicate element" << endl;}
cout << Z << endl;
Z.DistinctInsert(10,10);
cout << Z << endl;
}
（1）理想情况
跳表的实现代码：
View Code #if 1
#include <iostream>
#include <cmath>
#include <cstdlib>
using namespace std;
template <class E,class K>
class SkipList;
template <class E,class K>
class SkipNode{
friend class SkipList<E,K>;
SkipNode(int size){
link=new SkipNode<E,K>*[size];
}
~SkipNode(){
delete[] link;
}
private:
E data;
K key;
SkipNode<E,K>**link;
};
template<class E,class K>
class SkipList{
public:
SkipList(K large,int MaxE=10000,float p=0.5);
~SkipList();
bool Search(const K& k,E& e)const;
SkipList<E,K>& Insert(const K& k,const E& e);
SkipList<E,K>& Delete(const K& k,E& e);
void Output();
private:
int Level();
SkipNode<E,K>* SaveSearch(const K& k);
int MaxLevel;
int Levels;
int CutOff;
K TailKey;
SkipNode<E,K>* head;
SkipNode<E,K>* tail;
SkipNode<E,K>* *last;
};
template<class E,class K>
SkipList<E,K>::SkipList(K large,int MaxE,float p)
{
CutOff=p*RAND_MAX;
MaxLevel=ceil(log(MaxE*1.0)/log(1/p))-1;
TailKey=large;
Levels=0;
head=new SkipNode<E,K>(MaxLevel+1);
tail=new SkipNode<E,K>(0);
last=new SkipNode<E,K>* [MaxLevel+1];
tail->key=large;
for(int i=0;i<=MaxLevel;i++)
head->link[i]=tail;
}
template<class E,class K>
SkipList<E,K>::~SkipList()
{
SkipNode<E,K> *next;
while(head!=tail){
next=head->link[0];
delete head;
head=next;
}
delete tail;
delete [] last;
}
template<class E,class K>
bool SkipList<E,K>::Search(const K& k,E& e)const
{
if(k>=TailKey)
return false;
SkipNode<E,K> *p=head;
for(int i=Levels;i>=0;i--)
while(p->link[i]->key<k)
p=p->link[i];
e=p->link[0]->data;
K tmp=p->link[0]->key;
return e==tmp;
}
template<class E,class K>
SkipList<E,K>& SkipList<E,K>::Insert(const K& k,const E& e)
{
if(k>=TailKey)
throw "Bad Input";
SkipNode<E,K> *p=SaveSearch(k);
if(p->data==e)
throw "Bad Input";
int lev=Level();
if(lev>Levels){
lev=++Levels;
last[lev]=head;
}
SkipNode<E,K> *y=new SkipNode<E,K>(lev+1);
y->data=e;
y->key=k;
for(int i=0;i<=lev;i++){
y->link[i]=last[i]->link[i];
last[i]->link[i]=y;
}
return *this;
}
template<class E,class K>
SkipList<E,K>& SkipList<E,K>::Delete(const K& k,E& e)
{
if(k>=TailKey)
throw "Bad Input";
SkipNode<E,K> *p=SaveSearch(k);
if(p->data==e)
throw "Bad Input";
for(int i=0;i<=Levels&&last[i]->link[i]==p;i++)
last[i]->link[i]=p->link[i];
while(Levels>0&&head->link[Levels]==tail)
Levels--;
e=p->data;
delete p;
return *this;
}
template<class E,class K>
int SkipList<E,K>::Level()
{
int lev=0;
while(rand()<=CutOff)
lev++;
return lev<=MaxLevel?lev:MaxLevel;
}
template<class E,class K>
SkipNode<E,K>* SkipList<E,K>::SaveSearch(const K& k)
{
SkipNode<E,K> *p=head;
for(int i=Levels;i>=0;i--){
while(p->link[i]->key<k)
p=p->link[i];
last[i]=p;
}
return p->link[0];
}
template<class E, class K>
void SkipList<E,K>::Output()
{
SkipNode<E,K> *y = head->link[0];
for (; y != tail; y = y->link[0])
cout <<"("<<y->key<<","<< y->data <<") ";
cout << endl;
}
int main(void)
{
SkipList<int, long> S(10001, 100, 0.5);
int i, n = 20;
int data;
long key;
for (i = 1; i <= n; i++) {
data = i;
key = 2*i;
S.Insert(key,data);
}
S.Output();
for (i=1; i <= n+1; i++) {
data = n+i;
key = 2*i-1;
try {S.Insert(key,data);}
catch (...)
{cout << "Unable to insert duplicate (" <<key<<","<<data<<")"<< endl;}
}
S.Output();
for (i = 1; i <= n+1; i++) {
key = 2*i-1;
try {S.Delete(key,data);
cout << "Deleted (" << key << "," << data <<")"<< endl;}
catch (...)
{cout << "Delete of " << (2*i-1) << " failed" << endl;}
}
S.Output();
}
#endif
#include <iostream>
#include <cmath>
#include <cstdlib>
using namespace std;
template <class E,class K>
class SkipList;
template <class E,class K>
class SkipNode{
friend class SkipList<E,K>;
SkipNode(int size){
link=new SkipNode<E,K>*[size];
}
~SkipNode(){
delete[] link;
}
private:
E data;
K key;
SkipNode<E,K>**link;
};
template<class E,class K>
class SkipList{
public:
SkipList(K large,int MaxE=10000,float p=0.5);
~SkipList();
bool Search(const K& k,E& e)const;
SkipList<E,K>& Insert(const K& k,const E& e);
SkipList<E,K>& Delete(const K& k,E& e);
void Output();
private:
int Level();
SkipNode<E,K>* SaveSearch(const K& k);
int MaxLevel;
int Levels;
int CutOff;
K TailKey;
SkipNode<E,K>* head;
SkipNode<E,K>* tail;
SkipNode<E,K>* *last;
};
template<class E,class K>
SkipList<E,K>::SkipList(K large,int MaxE,float p)
{
CutOff=p*RAND_MAX;
MaxLevel=ceil(log(MaxE*1.0)/log(1/p))-1;
TailKey=large;
Levels=0;
head=new SkipNode<E,K>(MaxLevel+1);
tail=new SkipNode<E,K>(0);
last=new SkipNode<E,K>* [MaxLevel+1];
tail->key=large;
for(int i=0;i<=MaxLevel;i++)
head->link[i]=tail;
}
template<class E,class K>
SkipList<E,K>::~SkipList()
{
SkipNode<E,K> *next;
while(head!=tail){
next=head->link[0];
delete head;
head=next;
}
delete tail;
delete [] last;
}
template<class E,class K>
bool SkipList<E,K>::Search(const K& k,E& e)const
{
if(k>=TailKey)
return false;
SkipNode<E,K> *p=head;
for(int i=Levels;i>=0;i--)
while(p->link[i]->key<k)
p=p->link[i];
e=p->link[0]->data;
K tmp=p->link[0]->key;
return e==tmp;
}
template<class E,class K>
SkipList<E,K>& SkipList<E,K>::Insert(const K& k,const E& e)
{
if(k>=TailKey)
throw "Bad Input";
SkipNode<E,K> *p=SaveSearch(k);
if(p->data==e)
throw "Bad Input";
int lev=Level();
if(lev>Levels){
lev=++Levels;
last[lev]=head;
}
SkipNode<E,K> *y=new SkipNode<E,K>(lev+1);
y->data=e;
y->key=k;
for(int i=0;i<=lev;i++){
y->link[i]=last[i]->link[i];
last[i]->link[i]=y;
}
return *this;
}
template<class E,class K>
SkipList<E,K>& SkipList<E,K>::Delete(const K& k,E& e)
{
if(k>=TailKey)
throw "Bad Input";
SkipNode<E,K> *p=SaveSearch(k);
if(p->data==e)
throw "Bad Input";
for(int i=0;i<=Levels&&last[i]->link[i]==p;i++)
last[i]->link[i]=p->link[i];
while(Levels>0&&head->link[Levels]==tail)
Levels--;
e=p->data;
delete p;
return *this;
}
template<class E,class K>
int SkipList<E,K>::Level()
{
int lev=0;
while(rand()<=CutOff)
lev++;
return lev<=MaxLevel?lev:MaxLevel;
}
template<class E,class K>
SkipNode<E,K>* SkipList<E,K>::SaveSearch(const K& k)
{
SkipNode<E,K> *p=head;
for(int i=Levels;i>=0;i--){
while(p->link[i]->key<k)
p=p->link[i];
last[i]=p;
}
return p->link[0];
}
template<class E, class K>
void SkipList<E,K>::Output()
{
SkipNode<E,K> *y = head->link[0];
for (; y != tail; y = y->link[0])
cout <<"("<<y->key<<","<< y->data <<") ";
cout << endl;
}
int main(void)
{
SkipList<int, long> S(10001, 100, 0.5);
int i, n = 20;
int data;
long key;
for (i = 1; i <= n; i++) {
data = i;
key = 2*i;
S.Insert(key,data);
}
S.Output();
for (i=1; i <= n+1; i++) {
data = n+i;
key = 2*i-1;
try {S.Insert(key,data);}
catch (...)
{cout << "Unable to insert duplicate (" <<key<<","<<data<<")"<< endl;}
}
S.Output();
for (i = 1; i <= n+1; i++) {
key = 2*i-1;
try {S.Delete(key,data);
cout << "Deleted (" << key << "," << data <<")"<< endl;}
catch (...)
{cout << "Delete of " << (2*i-1) << " failed" << endl;}
}
S.Output();
}
#endif
（1）线性开型寻址
View Code #include <iostream>
using namespace std;
template<class E,class K>
class HashTable{
public:
HashTable(int divisior=11);
~HashTable(){
delete[] ht;
delete[] empty;
}
bool Search(const K& k,E& e)const;
HashTable<E,K>& Insert(const E& e);
void Output();
private:
int hSearch(const K& k)const;
int D;
E *ht;
bool *empty;
};
template<class E,class K>
HashTable<E,K>::HashTable(int divisior)
{
D=divisior;
ht=new E[D];
empty=new bool[D];
for(int i=0;i<D;i++)
empty[i]=true;
}
template<class E,class K>
bool HashTable<E,K>::Search(const K& k,E& e)const
{
int b=hSearch(k);
if(empty[b]||ht[b]!=k)
return false;
e=ht[b];
return true;
}
template<class E,class K>
HashTable<E,K>& HashTable<E,K>::Insert(const E& e)
{
K k=e;
int b=hSearch(k);
if(empty[b]){
empty[b]=false;
ht[b]=e;
return *this;
}
if(ht[b]==k)
throw "Bad Input";
throw "No mem";
return *this;
}
template<class E,class K>
void HashTable<E,K>::Output()
{
for(int i=0;i<D;i++){
if(empty[i])
cout<<"empty"<<endl;
else
cout<<ht[i]<<endl;
}
}
template<class E,class K>
int HashTable<E,K>::hSearch(const K& k)const
{
int i=k%D;
int j=i;
do{
if(empty[j]||ht[j]==k)
return j;
j=(j+1)%D;
}
while(j!=i);
return j;
}
int main(void)
{
int data;
long key;
HashTable<int, long> h(11);
data= 80;
h.Insert(data);
data= 40;
h.Insert(data);
data= 65;
h.Insert(data);
h.Output();
data= 58;
h.Insert(data);
data= 24;
h.Insert(data);
cout << ' ' << endl;
h.Output();
data= 2;
h.Insert(data);
data= 13;
h.Insert(data);
data= 46;
h.Insert(data);
data= 16;
h.Insert(data);
data= 7;
h.Insert(data);
data= 21;
h.Insert(data);
cout << ' ' << endl;
h.Output();
data=99;
try {h.Insert(data);}
catch (...)
{cout << " No memory for 99" << endl;}
}
using namespace std;
template<class E,class K>
class HashTable{
public:
HashTable(int divisior=11);
~HashTable(){
delete[] ht;
delete[] empty;
}
bool Search(const K& k,E& e)const;
HashTable<E,K>& Insert(const E& e);
void Output();
private:
int hSearch(const K& k)const;
int D;
E *ht;
bool *empty;
};
template<class E,class K>
HashTable<E,K>::HashTable(int divisior)
{
D=divisior;
ht=new E[D];
empty=new bool[D];
for(int i=0;i<D;i++)
empty[i]=true;
}
template<class E,class K>
bool HashTable<E,K>::Search(const K& k,E& e)const
{
int b=hSearch(k);
if(empty[b]||ht[b]!=k)
return false;
e=ht[b];
return true;
}
template<class E,class K>
HashTable<E,K>& HashTable<E,K>::Insert(const E& e)
{
K k=e;
int b=hSearch(k);
if(empty[b]){
empty[b]=false;
ht[b]=e;
return *this;
}
if(ht[b]==k)
throw "Bad Input";
throw "No mem";
return *this;
}
template<class E,class K>
void HashTable<E,K>::Output()
{
for(int i=0;i<D;i++){
if(empty[i])
cout<<"empty"<<endl;
else
cout<<ht[i]<<endl;
}
}
template<class E,class K>
int HashTable<E,K>::hSearch(const K& k)const
{
int i=k%D;
int j=i;
do{
if(empty[j]||ht[j]==k)
return j;
j=(j+1)%D;
}
while(j!=i);
return j;
}
int main(void)
{
int data;
long key;
HashTable<int, long> h(11);
data= 80;
h.Insert(data);
data= 40;
h.Insert(data);
data= 65;
h.Insert(data);
h.Output();
data= 58;
h.Insert(data);
data= 24;
h.Insert(data);
cout << ' ' << endl;
h.Output();
data= 2;
h.Insert(data);
data= 13;
h.Insert(data);
data= 46;
h.Insert(data);
data= 16;
h.Insert(data);
data= 7;
h.Insert(data);
data= 21;
h.Insert(data);
cout << ' ' << endl;
h.Output();
data=99;
try {h.Insert(data);}
catch (...)
{cout << " No memory for 99" << endl;}
}
（2）链表散列
View Code #include <iostream>
#include <map>
#include <vector>
#include <string>
#include <cstdlib>
using namespace std;
template <class K,class E>
class ChainHashTable{
public:
ChainHashTable(int div=11):D(div){
tab.resize(div);
}
bool Search(const K& k,E& e)const{
typename map<K,E>::iterator ite;
ite=tab[k%D].find(k);
if(ite==tab[k%D].end())
return false;
e=ite->second;
return true;
}
ChainHashTable& Insert(const K& k,const E& e){
tab[k%D].insert(pair<K,E>(k,e));
return *this;
}
ChainHashTable& Delete(const K& k){
tab[k%D].erase(k);
return *this;
}
void Output(ostream& os)const{
typename map<K,E>::const_iterator ite;
for(int i=0;i<D;i++){
os<<"tab["<<i<<"]:";
for(ite=tab[i].begin();ite!=tab[i].end();++ite){
os<<"<"<<ite->first<<","<<ite->second<<"> ";
}
os<<endl;
}
}
private:
int D;
vector<map<K,E> > tab;
};
template <class E,class K>
ostream& operator<<(ostream& os,const ChainHashTable<E,K>& cht){
cht.Output(os);
return os;
}
const string letters("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
string rand_str(int n){
string s(n,' ');
for(int i=0;i<n;i++){
int pos=rand()%52;
s[i]=letters[pos];
}
return s;
}
int main(){
ChainHashTable<int,string> ht(11);
int N=20;
for(int i=0;i<N;i++){
int val=rand()%100;
string str=rand_str(10);
ht.Insert(val,str);
}
cout<<"ok"<<endl;
cout<<ht<<endl;
}
#include <map>
#include <vector>
#include <string>
#include <cstdlib>
using namespace std;
template <class K,class E>
class ChainHashTable{
public:
ChainHashTable(int div=11):D(div){
tab.resize(div);
}
bool Search(const K& k,E& e)const{
typename map<K,E>::iterator ite;
ite=tab[k%D].find(k);
if(ite==tab[k%D].end())
return false;
e=ite->second;
return true;
}
ChainHashTable& Insert(const K& k,const E& e){
tab[k%D].insert(pair<K,E>(k,e));
return *this;
}
ChainHashTable& Delete(const K& k){
tab[k%D].erase(k);
return *this;
}
void Output(ostream& os)const{
typename map<K,E>::const_iterator ite;
for(int i=0;i<D;i++){
os<<"tab["<<i<<"]:";
for(ite=tab[i].begin();ite!=tab[i].end();++ite){
os<<"<"<<ite->first<<","<<ite->second<<"> ";
}
os<<endl;
}
}
private:
int D;
vector<map<K,E> > tab;
};
template <class E,class K>
ostream& operator<<(ostream& os,const ChainHashTable<E,K>& cht){
cht.Output(os);
return os;
}
const string letters("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
string rand_str(int n){
string s(n,' ');
for(int i=0;i<n;i++){
int pos=rand()%52;
s[i]=letters[pos];
}
return s;
}
int main(){
ChainHashTable<int,string> ht(11);
int N=20;
for(int i=0;i<N;i++){
int val=rand()%100;
string str=rand_str(10);
ht.Insert(val,str);
}
cout<<"ok"<<endl;
cout<<ht<<endl;
}
实现代码采用了STL中的map:
4. 散列与跳表的比较：
5.应用
LzW压缩
压缩代码的实现如下：下面的代码没有采用上面的等长位编码，而是采用的最显而易见的方式：
map<string,unsigned> compress(string & in_str,string& str_code){
map<string,unsigned> mp;
int N=Alpha;
int used=N;
for(int i=0;i<N;i++){
string key(1,'a'+i);
unsigned code=i;
mp.insert(pair<string,unsigned>(key,code));
}
typename map<string,unsigned>::iterator ite;
ostringstream oss;
size_t len=in_str.length();
if(len<2){
ite=mp.find(in_str.substr(0,1));
oss<<ite->second;
}
else{
string pcode;
pcode+=in_str[0];
for(int i=1;i<len;i++){
char c=in_str[i];
string key=pcode+c;
ite=mp.find(key);
if(ite!=mp.end()){
pcode=key;
}
else{
oss<<mp[pcode];
mp.insert(pair<string,unsigned>(key,used++));
pcode=c;
}
}
oss<<mp[pcode];
}
str_code=oss.str();
return mp;
}
map<string,unsigned> mp;
int N=Alpha;
int used=N;
for(int i=0;i<N;i++){
string key(1,'a'+i);
unsigned code=i;
mp.insert(pair<string,unsigned>(key,code));
}
typename map<string,unsigned>::iterator ite;
ostringstream oss;
size_t len=in_str.length();
if(len<2){
ite=mp.find(in_str.substr(0,1));
oss<<ite->second;
}
else{
string pcode;
pcode+=in_str[0];
for(int i=1;i<len;i++){
char c=in_str[i];
string key=pcode+c;
ite=mp.find(key);
if(ite!=mp.end()){
pcode=key;
}
else{
oss<<mp[pcode];
mp.insert(pair<string,unsigned>(key,used++));
pcode=c;
}
}
oss<<mp[pcode];
}
str_code=oss.str();
return mp;
}
LZW解压缩
解压缩代码：与压缩代码是对应的：
map<unsigned,string> decomp(string& str_code,string& out_str){
map<unsigned,string> mp;
int N=Alpha;
unsigned used=N;
for(int i=0;i<N;i++){
unsigned key=i;
string code(1,'a'+i);
mp.insert(make_pair(key,code));
}
typename map<unsigned,string>::iterator ite;
ostringstream oss;
size_t len=str_code.length();
if(len<2){
oss<<mp[(unsigned)(str_code[0]-'0')];
}
else{
unsigned pcode=(unsigned)(str_code[0]-'0');
oss<<mp[pcode];
for(int i=1;i<len;i++){
string prefix=mp[pcode];
char surfix;
string code;
unsigned key=used++;
unsigned ccode=(unsigned)(str_code[i]-'0');
ite=mp.find(ccode);
if(ite!=mp.end()){
oss<<ite->second;
surfix=(ite->second).at(0);
code=prefix+surfix;
// unsigned key=used++;
// mp.insert(make_pair(key,code));
}
else{
// string prefix=mp[pcode];
surfix=prefix[0];
code=prefix+surfix;
// unsigned key=used++;
oss<<code;
}
mp.insert(make_pair(key,code));
pcode=ccode;
}
}
out_str=oss.str();
return mp;
}
map<unsigned,string> mp;
int N=Alpha;
unsigned used=N;
for(int i=0;i<N;i++){
unsigned key=i;
string code(1,'a'+i);
mp.insert(make_pair(key,code));
}
typename map<unsigned,string>::iterator ite;
ostringstream oss;
size_t len=str_code.length();
if(len<2){
oss<<mp[(unsigned)(str_code[0]-'0')];
}
else{
unsigned pcode=(unsigned)(str_code[0]-'0');
oss<<mp[pcode];
for(int i=1;i<len;i++){
string prefix=mp[pcode];
char surfix;
string code;
unsigned key=used++;
unsigned ccode=(unsigned)(str_code[i]-'0');
ite=mp.find(ccode);
if(ite!=mp.end()){
oss<<ite->second;
surfix=(ite->second).at(0);
code=prefix+surfix;
// unsigned key=used++;
// mp.insert(make_pair(key,code));
}
else{
// string prefix=mp[pcode];
surfix=prefix[0];
code=prefix+surfix;
// unsigned key=used++;
oss<<code;
}
mp.insert(make_pair(key,code));
pcode=ccode;
}
}
out_str=oss.str();
return mp;
}
下面的代码是对上面压缩与解压缩的测试，包括测试压缩然后再解压缩得到的字符串与原字符串是否相等，压缩与解压所构造的字典是否一致，并给出了字典。
View Code #include <iostream>
#include <map>
#include <string>
#include <sstream>
#include <cstdlib>
using namespace std;
const string letters("ab");//cdefghijklmnopqrstuvwxyz");
const int Alpha=2;
template <class T>
void con_print(T& c){
typename T::iterator ite;
for(ite=c.begin();ite!=c.end();++ite){
cout<<*ite<<' ';
}
cout<<endl;
}
template <class K,class E>
void map_print(map<K,E>& mp){
typename map<K,E>::iterator ite;
for(ite=mp.begin();ite!=mp.end();++ite)
cout<<"<"<<ite->first<<","<<ite->second<<">"<<' ';
cout<<endl;
}
map<string,unsigned> compress(string & in_str,string& str_code){
map<string,unsigned> mp;
int N=Alpha;
int used=N;
for(int i=0;i<N;i++){
string key(1,'a'+i);
unsigned code=i;
mp.insert(pair<string,unsigned>(key,code));
}
typename map<string,unsigned>::iterator ite;
ostringstream oss;
size_t len=in_str.length();
if(len<2){
ite=mp.find(in_str.substr(0,1));
oss<<ite->second;
}
else{
string pcode;
pcode+=in_str[0];
for(int i=1;i<len;i++){
char c=in_str[i];
string key=pcode+c;
ite=mp.find(key);
if(ite!=mp.end()){
pcode=key;
}
else{
oss<<mp[pcode];
mp.insert(pair<string,unsigned>(key,used++));
pcode=c;
}
}
oss<<mp[pcode];
}
str_code=oss.str();
return mp;
}
map<unsigned,string> decomp(string& str_code,string& out_str){
map<unsigned,string> mp;
int N=Alpha;
unsigned used=N;
for(int i=0;i<N;i++){
unsigned key=i;
string code(1,'a'+i);
mp.insert(make_pair(key,code));
}
typename map<unsigned,string>::iterator ite;
ostringstream oss;
size_t len=str_code.length();
if(len<2){
oss<<mp[(unsigned)(str_code[0]-'0')];
}
else{
unsigned pcode=(unsigned)(str_code[0]-'0');
oss<<mp[pcode];
for(int i=1;i<len;i++){
string prefix=mp[pcode];
char surfix;
string code;
unsigned key=used++;
unsigned ccode=(unsigned)(str_code[i]-'0');
ite=mp.find(ccode);
if(ite!=mp.end()){
oss<<ite->second;
surfix=(ite->second).at(0);
code=prefix+surfix;
// unsigned key=used++;
// mp.insert(make_pair(key,code));
}
else{
// string prefix=mp[pcode];
surfix=prefix[0];
code=prefix+surfix;
// unsigned key=used++;
oss<<code;
}
mp.insert(make_pair(key,code));
pcode=ccode;
}
}
out_str=oss.str();
return mp;
}
bool map_equal(map<string,unsigned>& mp,map<unsigned,string>& mp2){
typename map<string,unsigned>::iterator ite;
typename map<unsigned,string>::iterator ite2;
for(ite=mp.begin();ite!=mp.end();++ite){
ite2=mp2.find(ite->second);
if(ite->first!=ite2->second)
return false;
}
return true;
}
int main1(){
string in_str("aaabbbbbbaabaaba");
string str_code;
map<string,unsigned> mp=compress(in_str,str_code);
cout<<in_str<<":"<<str_code<<endl;
map_print(mp);
return 0;
}
int main2(){
string str_code("0214537");
string out_str;
map<unsigned,string> mp=decomp(str_code,out_str);
cout<<str_code<<":"<<out_str<<endl;
map_print(mp);
return 0;
}
int main(){
int N=15;
for(int i=0;i<50;i++){
string in_str(N,' ');
for(int j=0;j<N;j++)
in_str[j]=letters[rand()%2];
string str_code;
map<string,unsigned> mp=compress(in_str,str_code);
string out_str;
map<unsigned,string> mp2=decomp(str_code,out_str);
cout<<in_str<<" ";
cout<<str_code<<" ";
cout<<out_str<<" ";
if(in_str==out_str)
cout<<"OK ";
else
cout<<"NO ";
if(map_equal(mp,mp2))
cout<<"OK ";
else
cout<<"NO ";
map_print(mp2);
}
}
#include <map>
#include <string>
#include <sstream>
#include <cstdlib>
using namespace std;
const string letters("ab");//cdefghijklmnopqrstuvwxyz");
const int Alpha=2;
template <class T>
void con_print(T& c){
typename T::iterator ite;
for(ite=c.begin();ite!=c.end();++ite){
cout<<*ite<<' ';
}
cout<<endl;
}
template <class K,class E>
void map_print(map<K,E>& mp){
typename map<K,E>::iterator ite;
for(ite=mp.begin();ite!=mp.end();++ite)
cout<<"<"<<ite->first<<","<<ite->second<<">"<<' ';
cout<<endl;
}
map<string,unsigned> compress(string & in_str,string& str_code){
map<string,unsigned> mp;
int N=Alpha;
int used=N;
for(int i=0;i<N;i++){
string key(1,'a'+i);
unsigned code=i;
mp.insert(pair<string,unsigned>(key,code));
}
typename map<string,unsigned>::iterator ite;
ostringstream oss;
size_t len=in_str.length();
if(len<2){
ite=mp.find(in_str.substr(0,1));
oss<<ite->second;
}
else{
string pcode;
pcode+=in_str[0];
for(int i=1;i<len;i++){
char c=in_str[i];
string key=pcode+c;
ite=mp.find(key);
if(ite!=mp.end()){
pcode=key;
}
else{
oss<<mp[pcode];
mp.insert(pair<string,unsigned>(key,used++));
pcode=c;
}
}
oss<<mp[pcode];
}
str_code=oss.str();
return mp;
}
map<unsigned,string> decomp(string& str_code,string& out_str){
map<unsigned,string> mp;
int N=Alpha;
unsigned used=N;
for(int i=0;i<N;i++){
unsigned key=i;
string code(1,'a'+i);
mp.insert(make_pair(key,code));
}
typename map<unsigned,string>::iterator ite;
ostringstream oss;
size_t len=str_code.length();
if(len<2){
oss<<mp[(unsigned)(str_code[0]-'0')];
}
else{
unsigned pcode=(unsigned)(str_code[0]-'0');
oss<<mp[pcode];
for(int i=1;i<len;i++){
string prefix=mp[pcode];
char surfix;
string code;
unsigned key=used++;
unsigned ccode=(unsigned)(str_code[i]-'0');
ite=mp.find(ccode);
if(ite!=mp.end()){
oss<<ite->second;
surfix=(ite->second).at(0);
code=prefix+surfix;
// unsigned key=used++;
// mp.insert(make_pair(key,code));
}
else{
// string prefix=mp[pcode];
surfix=prefix[0];
code=prefix+surfix;
// unsigned key=used++;
oss<<code;
}
mp.insert(make_pair(key,code));
pcode=ccode;
}
}
out_str=oss.str();
return mp;
}
bool map_equal(map<string,unsigned>& mp,map<unsigned,string>& mp2){
typename map<string,unsigned>::iterator ite;
typename map<unsigned,string>::iterator ite2;
for(ite=mp.begin();ite!=mp.end();++ite){
ite2=mp2.find(ite->second);
if(ite->first!=ite2->second)
return false;
}
return true;
}
int main1(){
string in_str("aaabbbbbbaabaaba");
string str_code;
map<string,unsigned> mp=compress(in_str,str_code);
cout<<in_str<<":"<<str_code<<endl;
map_print(mp);
return 0;
}
int main2(){
string str_code("0214537");
string out_str;
map<unsigned,string> mp=decomp(str_code,out_str);
cout<<str_code<<":"<<out_str<<endl;
map_print(mp);
return 0;
}
int main(){
int N=15;
for(int i=0;i<50;i++){
string in_str(N,' ');
for(int j=0;j<N;j++)
in_str[j]=letters[rand()%2];
string str_code;
map<string,unsigned> mp=compress(in_str,str_code);
string out_str;
map<unsigned,string> mp2=decomp(str_code,out_str);
cout<<in_str<<" ";
cout<<str_code<<" ";
cout<<out_str<<" ";
if(in_str==out_str)
cout<<"OK ";
else
cout<<"NO ";
if(map_equal(mp,mp2))
cout<<"OK ";
else
cout<<"NO ";
map_print(mp2);
}
}
下面是一个测试结果示例：
这儿存在的一个问题是：字符串不要太长，不然如果之巅长度超过10以后编码就乱了，因为编码之后的数字之间是没有空格进行分隔的。解决方法是可以换一种编码方式，可以采用大写字母。
上面的截图中也出现了字典长度超过10的情况，但是压缩和解压的结果仍然一致，原因是因为最后一个映射没有用到。
