Submission #9845

#	Time	Username	Problem	Language	Result	Execution time	Memory
9845		effserv	Uniting (kriii2_U)	C++98	1 / 4	12 ms	1088 KiB

U

#include <cstdio>
#include <algorithm>

using namespace std;

typedef long long ll;

int main()
{
	int N;
	scanf("%d", &N);

	ll a;
	scanf("%lld", &a);

	ll A = (ll)a;
	ll C = 0;
	for (int i = 0; i < N - 1; i++)
	{
		scanf("%lld", &a);
		C += A*a;
		A += a;
	}
	printf("%lld\n", C);

	ll mod = 1000000007;
	ll bigmod = 0x7fffffffffffffff;
	ll S = 1;

	for (int i = N; i >= 1; i--)
	{
		S*= (ll)i;
		S %= bigmod;
	}

	printf("%lld\n", S%mod);

	return 0;
}

• Subtask 1: 1 / 4