char *convert(char *dest)
{
    char *head=dest;
    char *ss=dest;
    char *src={0};   
    while(*dest)
    {
        if(*dest!=':')
        {
            dest++;
        }
        else
        {
            head=dest;
            dest--;
            while((*dest != ':')&&(strcmp(dest,ss)!=0))
            {
                *src=*dest;
                src++;
                dest--;
            }
            dest=head;
            dest++;
        }
    }   
    return src;
}
int main()
{
    char *s="ab:cd";
    printf("%s\n",convert(s));
}

你的意思是改为字符数组吗？

加了malloc还是错误，到底应该怎么写啊

正确答案应该要打印ba:dc

这么写我试了，虽然不崩溃了 但是却什么也不打印出来

void reverse_string(char *string, int element)
{
    char *end = string + element - 1;
    while(end > string)
    {
        char pairs[2] = {*string, *end};
        *end = pairs[0];
        *string = pairs[1];
        string++;
        end--;
    }
}

char *reverse(char *string)
{
    char *from = string;
    char *to = string;
    while(1)
    {
        if((*to == ':') || (*to == 0))
        {
            reverse_string(from, to - from);
            from = to + 1;
            if(*to == 0)
                break;
        }
        to++;
    }
    return string;
}
#include <stdio.h>
#include <string.h>

int main()
{
    char buf[64];
    const char *string = "156E:7601:XJHG";
    memset(buf, 0, sizeof(buf));
    memcpy(buf, string, strlen(string));
    printf("源:%s\t目的:%s\n", string, reverse(buf));
}

朋友的答案是这样

是不是加了static后是静态存储区，函数结束后不被销毁？