Submission #10061

#	Time	Username	Problem	Language	Result	Execution time	Memory
10061		effserv	Uniting (kriii2_U)	C++98	4 / 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 = 1e13;
    ll S = N;
 
    for (int i = N - 1; i >= 1; i--)
    {
        S *= (ll)i;
        S %= mod;
        S *= (ll)i;
        S %= mod;
    }
 
    printf("%lld\n", S%mod);
 
    return 0;
}

• Subtask 1: 4 / 4