数学趣题——求两个数的最大公约数和最小公倍数

#include <stdio.h>

int Gcd(int a, int b)
{
    int min;
    if (a <= 0 || b <= 0)
        return -1;
    if (a > b)
        min = b;
    else
        min = a;

    while (min)
    {
        if (a % min == 0 && b % min == 0)
            return min;

        min --;
    }

    return -1;
}

int Lcm(int a, int b)
{
    int max;
    if (a <= 0 || b <= 0)
        return -1;
    if (a > b)
        max = a;
    else
        max = b;

    while (max)
    {
        if (max % a == 0 && max % b == 0)
            return max;

        max++;
    }

    return -1;
}

int main()
{
    int a, b;
    printf("Input a b\n");
    scanf("%d %d", &a, &b);

    printf("the gcd is %d\n", Gcd(a, b));
    printf("the lcm is %d\n", Lcm(a, b));
    return 0;
}