1001 I love cube
一道数学题吧,其实比赛的时候没太看懂题,n=3,实在数不出72个等边三角形,n=4有288个,n每加一,多出n^3*8个等边三角形,这道题的规律就是对于n个结点的正立方体,1~n-1个(n-i)*8相加
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod = 1e9+7;
ll n;
ll ans;
int main(){
int t;
cin>>t;
while(t--){
cin>>n;
n=n-1;
if(n<=0){
cout<<"0"<<endl;
continue;
}
ll k=n%mod;
ll l=(n+1)%mod;
k=(k*k)%mod;
l=(l*l)%mod;
ans=(k*l)%mod;
ans=(2*ans)%mod;
cout<<ans<<endl;
}
return 0;
}