HDU 5086 Revenge of Segment Tree

题目链接：Revenge of Segment Tree

解题思路：有点意思的水题。。

看这个三角形

     1

    2 2

  3 4 3

 4 6 6 4

5 8 9 8 5

#include<cstdio>
#define ll long long
#define MOD 1000000007

using namespace std;

ll t, n, m, tem, ans;
ll i, j, k;
ll tot;

int main(){
scanf("%lld", &t);
while(t--){
scanf("%lld", &n);
ans = 0;
tot = 1;
for(i = 0; i < n; i++){
scanf("%lld", &tem);
tem = ((i + 1) * (n - i)) % MOD * tem % MOD;
ans = (ans + tem) % MOD;
}
printf("%lld\n", ans);
}
return 0;
}