c语言 8-8 求最大公约数

1、

#include <stdio.h>

int gcd(int x, int y)
{
    int max, min, tmp;
    if(x != y)
    {
    max = x > y ? x : y;
    min = x > y ? y : x;
    tmp = max % min;
    if(tmp != 0)
        gcd(min, tmp);
    else
        return min;
    }
}

int main(void)
{
    int a, b;
    puts("please input two integers.");
    printf("a = "); scanf("%d", &a);
    printf("b = "); scanf("%d", &b);
    
    printf("result: %d
", gcd(a, b));
    return 0;
}

2、

#include <stdio.h>

int gcd(int x, int y)
{
    int max, min, tmp;
    max = x > y ? x : y;
    min = x > y ? y : x;
    tmp = max % min;
    if(tmp != 0)
        gcd(min, tmp);
    else
        return min;    
} 

int main(void)
{
    int a, b;
    puts("please input two integers.");
    printf("a = "); scanf("%d", &a);
    printf("b = "); scanf("%d", &b);
    
    printf("result: %d
", gcd(a, b));
    
    return 0;
}

3、

#include <stdio.h>

int gcd(int x, int y)
{
    int max, min, tmp;
    max = x > y ? x : y;
    min = x > y ? y : x;
    tmp = max % min;
    if(tmp != 0)
        gcd(min, tmp);
    else
        return min;
}

int main(void)
{
    int a, b;
    puts("please input two integers.");
    do
    {
        printf("a = "); scanf("%d", &a);
        if(a <= 0)
            puts("the range of a is: > 0.");
    }
    while(a <= 0);
    
    do
    {
        printf("b = "); scanf("%d", &b);
        if(b <= 0)
            puts("the rage of b is: > 0");
    }
    while(b <= 0);
    
    printf("the result:  %d
", gcd(a, b));
    
    return 0 ;
}