（字符串）字符串的删除、复制、替换

#include <iostream>

using namespace std;

// delete some char, and replace blanket with %20
void stringDeleteAndReplace(char a[],char del){
//    int n=sizeof(a)/sizeof(a[0]);
    int len=0;
    int num_rep=0;
    // delete some char and record the num of ‘ ‘
    for(int i=0;a[i];i++){
        if(a[i]==‘ ‘) num_rep++;
        if(a[i]!=del) a[len++]=a[i];
    }
    a[len]=‘\0‘;

    // newlength after deletion and replacement
    int newlength=len+1+2*num_rep;
    int j=newlength-1;
    // from last to first
    for(int i=len;i>=0;i--){
        if(a[i]!=‘ ‘) a[j--]=a[i];
        else{
            a[j--]=‘0‘;
            a[j--]=‘2‘;
            a[j--]=‘%‘;
        }
    }
}

int main()
{
    char a[100]="This is my name: AndyJee";
    stringDeleteAndReplace(a,‘s‘);
    cout<<a<<endl;
    return 0;
}