HDU1576 A/B

#include<stdio.h>
int x, y;
void kzgcd(int a,int b)
{
    if(!b)
        x = 1, y = 0;
    else
    {
        kzgcd(b,a%b);
        int t = y;
        y = x-(a/b)*y;
        x = t;
    }
}
int main()
{
    int T, n, b;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d%d",&n,&b);
        kzgcd(b,9973);
        while(x < 0) x += 9973;
        printf("%d\n",x*n%9973);
    }
    return 0;
}

欧几里得拓展，理解不了欧几里得是干啥的。显摆到这里吧