【C语言】字符串替换空格:实现一个函数，把字符串里的空格替换成“%20”

//字符串替换空格:实现一个函数，把字符串里的空格替换成“%20”#include <stdio.h>#include <assert.h>void replace(char *src){assert(src);int OldLen = 0;                  //原字符串长度int NewLen = 0;                  //新字符串长度int BlackNum = 0;                //空格数量int NewBack = 0;                 //新字符串尾部int OldBack = 0;                 //原字符串尾部while (src[OldLen] != '\0'){if (src[OldLen] == ' '){BlackNum++;}OldLen++;}NewLen = OldLen + BlackNum * 2;OldBack = OldLen-1;NewBack = NewLen - 1;while (OldBack!=0){if (src[OldBack] == ' '){src[NewBack--] = '0';src[NewBack--] = '2';src[NewBack] = '%';}else{src[NewBack] = src[OldBack];}OldBack--;NewBack--;}}int main(){char p[20] = "hello world !";replace(p);printf("%s\n", p);return 0;return 0;}