字符串替换（新开辟空间）

 #include <iostream>

#include <string.h>

usingnamespace std;

char* replace_my(char* str,char c, const char* rc)// 调用函数前，保证str能展开空间

{ char* ret= str;

char* cp= str; size_t cnt= 0;

 int rcsize= (int)strlen(rc);

while (*cp) {if (*cp== c)

 cnt++;// 统计找到 c 的次数++cp;

 }

if (cnt <= 0)// 没找到 c

return ret; cp = str;

int bufsize = strlen(str) + rcsize * cnt+ 1;

 char* buf = newchar[bufsize];// 建立缓冲区buf

char * ps= buf; while (*cp) {*ps = *cp;

if (*cp== c) { // 替换字符 c 为字符串 rc

memcpy(ps, rc, rcsize); ps += (rcsize-1);

}

++cp;

++ps; }

*ps ='\0';// 封闭缓冲区buf

strcpy(str , buf); delete[] buf;

return ret;}

int main()

{ char str[1024];

strcpy(str, "abcdefgabcdefgcccac");

cout << str<< endl; replace_my(str,'c'," <cccccccccccccccccccccccc>");

cout << str<< endl << endl;

return 0;}