| # | Time | Username | Problem | Language | Result | Execution time | Memory | 
|---|---|---|---|---|---|---|---|
| 9634 | pichulia | Uniting (kriii2_U) | C++98 | 0 ms | 0 KiB | 
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#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]);
}
