c语言 411 逆向输出输入的整数值（同时输出原始数据）

1、while语句

#include <stdio.h>

int main(void)
{
    int i;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is > 0");
    }
    while (i <= 0);
    
    printf("%d's reversed result is: ", i);
    while (i > 0)
    {
        printf("%d", i % 10);
        i /= 10;
    }
    putchar('\n');
    return 0;
}

#include <stdio.h>

int main(void)
{
    int i, j = 0;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is: > 0");
    }
    while (i <= 0);
    
    printf("the reversed result of %d is: ", i);
    while (i > 0)
    {
        j = j * 10 + i % 10;
        i /= 10;
    }
    printf("%d\n", j);
    
    return 0;
}

2、for语句

#include <stdio.h>

int main(void)
{
    int i;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is: > 0");
    }
    while (i <= 0);
    
    printf("the reversed result of %d is: ", i);
    for (i; i > 0; i /= 10)
    {
        printf("%d", i % 10);
    }
    putchar('\n');
    return 0;
}

#include <stdio.h>

int main(void)
{
    int i, j = 0;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is: > 0");
    }
    while (i <= 0);
    
    printf("the reversed result of %d is: ", i);
    for (i; i > 0; i /= 10)
    {
        j = j * 10 + i % 10;
    }
    printf("%d\n", j);
    
    return 0;
}

3、do语句

#include <stdio.h>

int main(void)
{
    int i;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is: > 0");
    }
    while (i <= 0);
    
    printf("the reversed result of %d is: ", i);
    do
    {
        printf("%d", i % 10);
        i /= 10;
    }
    while (i > 0);
    putchar('\n');
    
    return 0;
}

#include <stdio.h>

int main(void)
{
    int i, j = 0;
    puts("please input an integer.");
    do
    {
        printf("i = "); scanf("%d", &i);
        if (i <= 0)
            puts("the range of i is: > 0");
    }
    while (i <= 0);
    
    printf("the reversed result of %d is: ", i);
    do
    {
        j = j * 10 + i % 10;
        i /= 10;
    }
    while (i > 0);
    printf("%d\n", j);
    
    return 0;
}