Submission #9689

#	TimeUTC-0	Username	Problem	Language	Result	Execution time	Memory
9689	2014-09-28 08:07:03	shashack	Uniting (kriii2_U)	C++98	4 / 4	28 ms	9364 KiB

U

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
#include<iostream>
using namespace std;
int main(){
  int n; cin >> n;
  long long val[1000000+1];
  for (int i = 0; i < n; i++){
    cin >> val[i];
  }
  long long ret = 0;
  for (int i = 1; i < n; i++){
    ret += val[i] * val[i - 1];
    val[i] = val[i] + val[i - 1];
  }
  long long count = 1;
  for (int i = n; i >= 2; i--){
    count = (((count % 1000000007) * (i) % 1000000007) * (i - 1)) % 1000000007;
  }
  cout << ret << endl << count << endl;
}
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

• Subtask 1: 4 / 4