数据结构 两栈共享
将编号0和1两个栈存放于一个数组空间V[m]中，栈底分别位于数组的两端。当0号栈的栈顶指针top[0] = -1时该栈为空，当1号栈的栈顶指针top[1]等于m时，该栈为空。两个栈均从两端向中间增长
#include <stdio.h>
#include <stdlib.h>
#define InitMaxsize 3//栈最大可容纳元素个数
typedef int elem;
typedef struct
{
int top[2], bot[2];//定义栈顶和栈底指针
elem *V; //栈数组
int m; //栈最大可容纳元素个数
}DblStack;
//初始化双栈
void InitDblStack(DblStack &stack)
{
elem *arr = (elem*)malloc(sizeof(elem));//申请空间
stack.V = arr; //将V指针指向申请的空间
stack.m = InitMaxsize; //初始化栈最大可容纳最大元素个数
stack.top[0] = -1; //左栈栈顶指针初始化
stack.top[1] = stack.m - 1; //右栈栈顶指针初始化
stack.bot[0] = 0; //左栈栈底指针初始化
stack.bot[1] = stack.m-1; //右栈栈底指针初始化
}
//判断总体是否为空栈
int EmptyDblStack(DblStack stack)
{
if(stack.top[0] == -1 && stack.top[1] == stack.m-1)
return 1; //若是返回1
return 0; //否则返回0
}
//判断左栈是否为空栈
int EmptyLeft(DblStack stack)
{
if(stack.top[0] == -1)
return 1; //若是返回1
return 0; //否则返回0
}
//判断右栈是否为空栈
int EmptyRight(DblStack stack)
{
if(stack.top[1] == stack.m-1)
return 1; //若是返回1
return 0; //否则返回0
}
//判断是否为满栈
int FullDblStack(DblStack stack)
{
if(stack.top[1] == stack.top[0] || stack.top[0] >= stack.m || stack.top[1] < 0 )
//三种满栈情况左右两栈中间相遇，左栈满，右栈满
return 1;//满栈返回1
return 0;//否则返回0
}
//左栈进栈
int pushLeft(DblStack &stack, elem e)
{
if (FullDblStack(stack) == 1)//判断是否为满栈
{
printf("栈已满不能进行进栈操作\n");
return 0; //满栈返回0
}
stack.top[0]++; //左栈栈顶指针加一
stack.V[stack.top[0]] = e; //将数据元素进栈
return 1; //完成操作返回1
}
//右栈进栈
int pushRight(DblStack &stack, elem e)
{
if (FullDblStack(stack) == 1)//判断是否为满栈
{
printf("栈已满，无法进行进栈操作\n");
return 0; //满栈返回0
}
stack.V[stack.top[1]] = e; //将数据元素进栈
stack.top[1]--; //右栈栈顶指针加一
return 1;
}
//左栈出栈
elem popLeft(DblStack &stack)
{
if (EmptyLeft(stack) == 1)//判断是否为空栈
{
printf("左栈已空，无法进行出栈操作\n");
return 0; //空栈返回0
}
elem e = stack.V[stack.top[0]]; //取出栈顶数据元素
stack.top[0]--; //左栈栈顶元素减一
return e; //返回原栈顶元素
}
//右栈出栈
elem popRight(DblStack &stack)
{
if (EmptyRight(stack) == 1) //判断是否为空栈
{
printf("右栈已空，无法进行出栈操作\n");
return 0; //空栈返回0
}
stack.top[1]++; //右栈栈顶指针加一
elem e = stack.V[stack.top[1]]; //取出右栈栈顶元素
return e; //返回原栈顶元素
}
//遍历双栈
void printDblStack(DblStack stack)
{
for (int i = 0; i <= stack.top[0]; i++) //输出左栈
{
printf("|%d| ", stack.V[i]);
}
for(int i = ++stack.top[1]; i < stack.m; i++)//输出右栈
{
printf("|%d| ", stack.V[i]);
}
printf("\n");
}
//调试
int main()
{
DblStack stack;
InitDblStack(stack); //初始化双栈
printf("双栈%s空栈\n", EmptyDblStack(stack) == 1?"是":"不是"); //判断总体是否为空栈
pushLeft(stack, 1); //左栈进栈
pushLeft(stack, 2); //左栈进栈
pushRight(stack, 3); //右栈进栈
printf("双栈%s满栈\n", FullDblStack(stack) == 1?"已":"未");//判断是否为满栈
popLeft(stack);
popRight(stack);
popRight(stack);
printDblStack(stack);
return 0;
}
王鹏霄 21:15:19
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
class SElemType {
public:
int data;
SElemType(int data=0): data(data) {}
};
typedef struct
{
int top[2], bot[2];
SElemType* V;
int m;
} DblStack;
void init(DblStack& dblStack, int size) {
dblStack.m = size;
dblStack.V = new SElemType[size];
dblStack.bot[0] = 0;
dblStack.bot[1] = size - 1;
dblStack.top[0] = -1;
dblStack.top[1] = size;
}
void release(DblStack& dblStack) {
delete[] dblStack.V;
}
void display(const DblStack& dblStack) {
for (int i = dblStack.bot[0]; i <= dblStack.top[0]; i++) {
cout << (dblStack.V[i].data) << " ";
}
cout << " <> ";
for (int i = dblStack.bot[1]; i >= dblStack.top[1]; i--) {
cout << (dblStack.V[i].data) << " ";
}
cout << endl;
}
bool isEmpty(DblStack& dblStack, int id) {
if (id == 0) {
return dblStack.top[0] == -1;
}
else if (id == 1) {
return dblStack.top[1] == dblStack.m;
}
else {
return true;
}
}
bool isFull(DblStack& dblStack){
return (dblStack.top[1] - dblStack.top[0] == 1);
}
void push(DblStack& dblStack, int id, SElemType elem) {
if (!isFull(dblStack)) {
if (id == 0) {
dblStack.V[++dblStack.top[0]] = elem;
}
else if (id == 1) {
dblStack.V[--dblStack.top[1]] = elem;
}
}
}
void pop(DblStack& dblStack, int id) {
if (!isEmpty(dblStack, id)) {
if (id == 0) {
dblStack.top[0] --;
}
else if (id == 1) {
dblStack.top[1] ++;
}
}
}
int main() {
DblStack stack;
init(stack, 10);
push(stack, 0, SElemType(1));
push(stack, 0, SElemType(2));
push(stack, 0, SElemType(3));
push(stack, 0, SElemType(4));
push(stack, 1, SElemType(5));
push(stack, 1, SElemType(6));
push(stack, 1, SElemType(7));
push(stack, 1, SElemType(8));
push(stack, 1, SElemType(9));
push(stack, 1, SElemType(10));
push(stack, 1, SElemType(11));
push(stack, 0, SElemType(12));
display(stack);
pop(stack, 0);
pop(stack, 1);
pop(stack, 1);
display(stack);
pop(stack, 0);
pop(stack, 0);
pop(stack, 0);
pop(stack, 0);
pop(stack, 1);
pop(stack, 1);
pop(stack, 1);
pop(stack, 1);
pop(stack, 1);
display(stack);
release(stack);
return 0;
}
