# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
9634 | 2014-09-28T07:46:09 Z | pichulia | Uniting (kriii2_U) | C++ | 0 ms | 0 KB |
#include<stdio.h> #define M 1000000007LL int n; long long int a[100009]; long long int f[100009]; long long int g[100009]; long long int s,t,u; int main() { scanf("%d",&n); long long int i,j, k; f[0] = 1; g[0] = 1; for(i=0;i<n;i++) { scanf("%lld",&a[i]); s = (s+a[i])%M; t = (t+a[i]*a[i])%M; } g[1] = 1; for(i=2;i<=n;i++) { g[i] = (g[i-1]*(i*(i-1)))%M; } u = (s*s-t); u = u/2 printf("%lld\n%lld\n",u,g[n]); }