ccpc 2018 final G - Pastoral Life in Stardew Valley

 

 

 

 

 

 

 

#include <iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
#define ll long long 
const int N  =100009;
const ll mod  = 1000000007;
ll c[N][10];
void init()
{
    c[0][0] =1ll;
    for(int i =1;i<N;i++){
        for(int j =0;j<=5;j++){
            if(j==0||j==i)  c[i][j]=1ll;
            else c[i][j]  =  (c[i-1][j-1]%mod+c[i-1][j]%mod)%mod;
        }
    }
}
int  t,n,m;
int  main()
{
    init();
    scanf("%d",&t);
    for(int i =1;i<=t;i++)
    {
        scanf("%d%d",&n,&m);
        if(n<3||m<3) printf("Case %d: 0\n",i);
        else{
            ll  x = (c[n][3]+c[n][4])%mod;
            ll y = (c[m][3]+c[m][4])%mod;
            x=(x*y)%mod;
             printf("Case %d: %lld\n",i,x);
        }
    }
    return  0;
}