Submission #9351

#	Time	Username	Problem	Language	Result	Execution time	Memory
9351		lemonsqueeze	Uniting (kriii2_U)	C++98	4 / 4	12 ms	1868 KiB

U

#include <cstdio>

const int N = 100000;
typedef long long int64;

const int64 MOD = 1000000007;

int n;
int64 s[N];

int main(void) {
	scanf("%d", &n);
	int64 sum = 0;
	for (int i = 0; i < n; i++) {
		scanf("%lld", &s[i]);
		sum += s[i];
	}
	int64 ans = 0, kase = 1;
	for (int i = 0; i < n; i++) {
		sum -= s[i];
		ans += sum * s[i];
	}
	printf("%lld\n", ans);
	for (int i = 1; i <= n-1; i++) {
		kase = (kase * (int64)i) % MOD;
	}
	kase = (kase*kase)%MOD;
	kase = kase*n%MOD;
	printf("%lld\n", kase);
	return 0;
}

• Subtask 1: 4 / 4