在写代码中出现了错误

问题在这，目的是将一个字符串倒序

供参考：

#include <stdio.h>
#include <string.h>
#include <malloc.h>
int main()
{
    char* src = "hello,world";
    char* dest = NULL;
    int len = strlen(src);
    dest = (char*)malloc(len + 1);
    char* d = dest;
    char* s = src + len - 1;
    while (len-- != 0)
        *d++ = *s--;
    *d = '\0';
    printf("%s",dest);
    return 0;
}