程序代码：

#include"stdio.h"
#define QW "quit"
char *ar(char *p){
    char *q;
    int i;
    i=1;
    for(*(p+strlen(p)-i);*p;q++,i++)
        *q=*(p+strlen(p)-i);
    *q='\0';
    return q;
}
int main(void){
    char *t;
    char *w;
    t=(char *)malloc(sizeof(char)*100);
    printf("输入字符串：");
    while(strcmp(gets(t),QW)){
        w=ar(t);
        printf("%s\n",w);
        printf("输入字符串：");
    }
    return 0;
}

程序代码：

#include <stdio.h>

#define MAX_LEN 4096

int main(void)
{
    char c, s[MAX_LEN] = {0}, *sp;

    for (sp = s; (c = getchar()) != '\n' && c != EOF; *sp++ = c);
    for (; --sp >= s; putchar(*sp));
    printf("\n");
}

[此贴子已经被作者于2020-6-14 20:06编辑过]

程序代码：

#include "stdio.h"
#include "string.h"
#include "stdlib.h"
#define QW "quit"
char * gets(char *);
char *ar(char *p) {
    char *begin = p;
    char *last = p + strlen(p)-1;
    while (begin < last) {
        char temp = *last;
        *last = *begin;
        *begin = temp;
        begin++;
        last--;
    }
    return p;
}
int main(void) {
    char *t;
    char *w;
    t = (char *)malloc(sizeof(char) * 100);
    printf("输入字符串：");
    while (strcmp(gets(t), QW)) {
        w = ar(t);
        printf("%s\n", w);
        printf("输入字符串：");
    }
    free(t);
    return 0;
}

[此贴子已经被作者于2020-6-15 14:17编辑过]

程序代码：

char *ar(char *p){
    char *q;
    q=(char *)malloc(sizeof(char)*100);
    int i,j;
    j=strlen(p);
    for(i=1;i<=j;q++,i++){
        *q=*(p+j-i);
    }
    *q='\0';
    return q;
}

程序代码：

char *ar(char *p) {
    char *q;
    q = (char *)malloc(sizeof(char) * 100);
    char *qq = q;
    int i, j;
    j = strlen(p);
    for (i = 1; i <= j; qq++, i++) {
        *qq = *(p + j - i);
    }
    *qq = '\0';
    return q;
}

程序代码：

char *ar(char *p) {
    char *q;
    q = (char *)malloc(sizeof(char) * 100);
    int i, j;
    j = strlen(p);
    for (i = 1; i <= j; q++, i++) {
        *q = *(p + j - i);
    }
    *q = '\0';
    q -= j;
    return q;
}

[此贴子已经被作者于2020-6-16 13:15编辑过]