c语言 9-9

1、

#include <stdio.h>

void put(char x[])
{
    int len = 0;
    while(x[len])
        len++;
    int i;
    for(i = 0; i < len / 2; i++)
    {
        int tmp = x[i];
        x[i] = x[len - 1 - i];
        x[len - 1 - i] = tmp;
    }
}

int main(void)
{
    char str[128];
    printf("str: "); scanf("%s", str);
    put(str);
    int i = 0;
    while(str[i])
        putchar(str[i++]);
    return 0;
}

2、

#include <stdio.h>

void put(char x[])
{
    int len = 0;
    while(x[len])
        len++;
    char tmp[len];
    int i = 0;
    while(x[i])
    {
        tmp[i] = x[len - 1 - i];
        i++;
    }
    i = 0;
    while(tmp[i])
    {
        x[i] = tmp[i];
        i++;
    }
}

int main(void)
{
    char str[128];
    printf("str: "); scanf("%s", str);
    put(str);
    int i = 0;
    while(str[i])
        putchar(str[i++]);
    return 0;
}