字符串填充，用三个字符将空格代替，空格后边字母后移，不覆盖原来字母

#include<iostream>

#include<string>

using namespace std;

class stu{

public:

void replaceSpace(char **str1,int *length) {

                   char *ch=new char[100];

                   char *ch1,*ch2;

                   int len;

                   len=0;

        ch1=*str1;

        ch2=ch;

        while(*ch1){

            if(*ch1!=' '){

               *ch=*ch1;

                               ch++;   

               len++;

            }

            else{                             

                                       *ch='%';ch++;

                  *ch='2';ch++;

                  *ch='0';ch++;

               len=len+3;

             }

                            ch1++;

         }

        *length=len;

        *str1=ch2;

                   *ch='\0';

                   cout<<strlen(ch2)<<endl;        

                   printf("%s\n",*str1);

                   //*length=*len;

         }

};

void main(){

                   int length1=0;

                   char *str1="my name is chen xiao meng";

                   length1=strlen(str1);

                   printf("%s\n",str1);

                   cout<<length1<<endl;    

                   cout<<str1<<endl;

                   stu a;

                   a.replaceSpace(&str1,&length1);  

                   printf("%s\n%d\n",str1,length1);

}