统计短文中各字符的频度

//主要算法，二叉排序树的查找

//以出现的各字符构成一棵二叉排序树，针对每一个字符在二叉树中查找，如果找到了就增加计数，否则就插入
#include<iostream>
#include<string>
#include<fstream>
using namespace std;
typedef char KeyType;
struct BstNode 
{
    KeyType data;
    int num;
    BstNode *lch,*rch;
};
class BstTree
{
private:
    BstNode *root;
    BstNode* insert(BstNode *t,BstNode *s);
    void inorder(ofstream& outfile,BstNode *p);
    void deletenode(BstNode *p);

public:
    BstTree(){root=NULL;}
    ~BstTree(){delete(root);root=NULL;}
    void read_creat(ifstream& infile);
    void print_inorder(ofstream& outfile)
        {inorder(outfile,root);}
};
BstNode* BstTree::insert(BstNode *t,BstNode *s)
{
    if(t==NULL){t=s;t->num=1;}
    else if(t->data==s->data){delete(s);s=NULL;t->num++;}
    else 
    {
        if(t->data>s->data)t->lch=insert(t->lch,s);
        else t->rch=insert(t->rch,s);
    }
    return t;
}
void BstTree::read_creat(ifstream& infile)
{
    char ch; 
    infile.get(ch);
    while(infile)
    {
        BstNode *s;s=new BstNode;s->data=ch;s->num=1;s->lch=s->rch=NULL;
        root=insert(root,s);
        infile.get(ch);
    }
}
void BstTree::deletenode(BstNode *p)
{
    if(p!=NULL)
    {
        deletenode(p->lch);deletenode(p->rch);
        delete p;
    }
}
void BstTree::inorder(ofstream& outfile,BstNode *p)
{
    if(p!=NULL)
    {
        inorder(outfile,p->lch);
        outfile<<p->data<<"    "<<p->num<<endl;
        inorder(outfile,p->rch);
    }
}
void main()
{
    ifstream infile;ofstream outfile;infile.open("E:\\c++.txt");
    if(!infile){cout<<"open file failure!\n";return;}    
    outfile.open("E:\\b++.txt");

    BstTree tree;
    tree.read_creat(infile);
    tree.print_inorder(outfile);
    infile.close();outfile.close();
}    

　　

                           //读取文本中的字符并计算出各字母出现的次数

#include<iostream>
#include<fstream>
#include<cctype>

using namespace std;

void initialize(int& lc,int list[]);
void copyText(ifstream& intext,ofstream& outtext,char& ch,int list[]);
void characterCount(char ch,int list[]);
void writeTotal(ofstream& outtext,int lc,int list[]);
int main()
{
    int lineCount;
    int listLetter[26];
    char ch;
    ifstream infile;
    ofstream outfile;
    infile.open("C:\\c++.txt");
    if(!infile)
    {
        cout<<"Cannot open input file."<<endl;
        return 1;
    }
    outfile.open("C:\\b++.txt");
    initialize(lineCount,listLetter);
    infile.get(ch);
    while(infile)
    {
        copyText(infile,outfile,ch,listLetter);
        lineCount++;    
        infile.get(ch);
    }
    writeTotal(outfile,lineCount,listLetter);
    infile.close();
    outfile.close();
    
    return 0;
}
void initialize(int& lc,int list[])
{
    int j;
    lc=0;
    for(j=0;j<26;j++)
        list[j]=0;
}

void copyText(ifstream& intext,ofstream& outtext,char& ch,int list[])
{
    while(ch!='\n')
    {
        outtext<<ch;                      //输出原文本的信息
        characterCount(ch,list);
        intext.get(ch);
    }
    outtext<<ch;                         //原文本断行时新文本也断行
}
void characterCount(char ch,int list[])
{
    int index;
    ch=toupper(ch);
    index=static_cast<int>(ch)-65;
    if(0<=index && index<26)
        list[index]++;
}
void writeTotal(ofstream& outtext,int lc,int list[])
{
    int index;
    outtext<<endl<<endl;
    outtext<<"The number of lines="<<lc<<endl;
    for(index=0;index<26;index++)
        outtext<<static_cast<char>(index+65)<<" count = "<<list[index]<<endl;
}

/*
sample
C:\\c++.txt:

fwwwewefqtgqtggrqg
rgqeerghhwhwewhtfwqfqgqrewgqe
gqrgergqegrq
cwoifuqiwofjeiopjwe
svjxvzvmxnbdmeioejgeorigjqioadf;klsajfpoiqfew;fjwf
54651844fwgqrwegergqwerea


C:\\b++.txt:

fwwwewefqtgqtggrqg
rgqeerghhwhwewhtfwqfqgqrewgqe
gqrgergqegrq
cwoifuqiwofjeiopjwe
svjxvzvmxnbdmeioejgeorigjqioadf;klsajfpoiqfew;fjwf
54651844fwgqrwegergqwerea


The number of lines=6
A count = 3
B count = 1
C count = 1
D count = 2
E count = 19
F count = 12
G count = 17
H count = 4
I count = 7
J count = 7
K count = 1
L count = 1
M count = 2
N count = 1
O count = 7
P count = 2
Q count = 16
R count = 11
S count = 2
T count = 3
U count = 1
V count = 3
W count = 17
X count = 2
Y count = 0
Z count = 1

*/