題意:給出三個數的gcd,lcm,求這三個數的全部的可能
思路 :設x,y,z的gcd為d,那么設x=d*a,y=d*b,z=d*c。a,b。c肯定是互質的。那么lcm=d*a*b*c,所以我們能夠得到a*b*c=lcm/gcd=ans,將ans分解因數后,那么每次都要分配每一個因數的個數,如果某個因數的個數為n,一定要有兩個分配到n,0,所以是6種
#include <iostream>
#include <cstdio>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;int n,m;
int num[1000000];int main(){int t;scanf("%d",&t);while (t--){scanf("%d%d",&n, &m);if (m%n != 0){printf("0\n");continue;}m /= n;int cnt = sqrt(m+0.5);int k = 0;for (int i = 2; i <= cnt && m > 1; i++){if (m % i == 0){num[k] = 0;while (m%i == 0){++num[k];m /= i;}++k;}}if (m != 1)num[k++] = 1;int ans = 1;for (int i = 0; i < k; i++)ans = ans*num[i]*6;cout << ans << endl;}return 0;
}