Submission #9644

#	Time	Username	Problem	Language	Result	Execution time	Memory
9644		yukariko	Uniting (kriii2_U)	C11	1 / 4	12 ms	1748 KiB

U

#include <stdio.h>
int main()
{
  int N;
  long long s[100001];
  long long cnt;
  long long sum;
  int i,j;
  
  cnt = 1;
  sum = 0;
  
  scanf("%d",&N);  
  for(i=0;i<N;i++)scanf("%lld",s+i); 
  for(i=0;i<N-1;i++)
  {
    sum += s[i]*s[i+1];
    s[i+1] += s[i];
    cnt = (cnt*(N-i)*(N-i-1));
    if(cnt > 1000000007LL * 2) cnt%=1000000007LL;
  }
  printf("%lld\n",sum);
  printf("%lld\n",cnt%1000000007LL);
}

• Subtask 1: 1 / 4