字符串反转

#include <stdio.h>
#include <string.h>

char *myStrreverse(char *s);

int
main(void)
{
    char s[] = "hello";
    char *r = myStrreverse(s);
    printf(r);

    return 0;
}

char *
myStrreverse(char *s)
{
    if (NULL == s)
        return NULL;

    if (*s) {
        char *h, *t;

        h = s;
        t = s + strlen(s) - 1;

        while (h < t) {
            char tmp;

            tmp = *h;
            *h = *t;
            h++;
            *t = tmp;
            t--;
        }
    }

    return s;
}