Submission #9782

#	Time	Username	Problem	Language	Result	Execution time	Memory
9782		kkjjkk	Uniting (kriii2_U)	C++98	1 / 4	16 ms	4800 KiB

U

#include <algorithm>
#include <iostream>
#include <cstdio>
using namespace std;
long long h[100005];
long long f[100005], m = 1000000007, nn[100005], tw[100005];

int main()
{
    int n;
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%lld", &h[i]);
    f[1] = 1;
    for(int i = 2; i < 100005; i++) { f[i] = f[i - 1] * i; f[i] %= m; }
    tw[1] = 2;
    for(int i = 2; i < 100005; i++) { tw[i] = tw[i - 1] * 2; tw[i] %= m; }
    if(n == 1) { printf("0\n"); printf("1"); }
    else if(n == 2) { printf("%lld\n", h[0] * h[1]); printf("2"); }
    else {
         //sort(h, h + n);
         
         long long a = h[0] + h[1];
         long long b = h[0] * h[1];
         long long c, d;//, m = 1000000007;
         for(int i = 2; i < n; i++) {
              /*c = a + h[i];
              d = ((a % m) * h[i]) % m; //d %= ;
              a = c;
              b = ((b % m) + (d % m)) % m; //b %= 1000000007;*/
              c = a * h[i]; //c %= m;
              a += h[i]; b += c; //b %= m;
         }
         printf("%lld\n", b);
         printf("%lld", (f[n] * tw[n - 2]) % m);
         
    }
}

• Subtask 1: 1 / 4