Submission #19636

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19636	2016-02-25T02:59:08 Z	yongwhan	Σ (kriii4_P2)	C++	100 / 100	17 ms	1720 KB

P2

#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

const int mod=1e9+7;

ll exp(ll a, ll b, ll m) {
  ll r=1;
  while(b) {
    if(b%2) r=(r*a)%m;
    a=(a*a)%m;
    b/=2;
  }
  return r;
}

ll inv(ll a, ll m) {
  return exp(a,m-2,m);
}

int main() {
  int m; cin>>m;
  ll ret=0;
  for (int i=0; i<m; i++) {
    ll n,s; cin>>n>>s;
    ret=(ret+s*inv(n,mod))%mod;
  }
  cout << ret << endl;
  return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	17 ms	1720 KB	Output is correct
2	Correct	15 ms	1720 KB	Output is correct
3	Correct	13 ms	1720 KB	Output is correct
4	Correct	14 ms	1720 KB	Output is correct
5	Correct	14 ms	1720 KB	Output is correct
6	Correct	14 ms	1720 KB	Output is correct
7	Correct	13 ms	1720 KB	Output is correct
8	Correct	12 ms	1720 KB	Output is correct
9	Correct	15 ms	1720 KB	Output is correct
10	Correct	11 ms	1720 KB	Output is correct
11	Correct	11 ms	1720 KB	Output is correct
12	Correct	15 ms	1720 KB	Output is correct
13	Correct	12 ms	1720 KB	Output is correct
14	Correct	12 ms	1720 KB	Output is correct
15	Correct	11 ms	1720 KB	Output is correct
16	Correct	14 ms	1720 KB	Output is correct
17	Correct	9 ms	1720 KB	Output is correct
18	Correct	13 ms	1720 KB	Output is correct
19	Correct	14 ms	1720 KB	Output is correct
20	Correct	15 ms	1720 KB	Output is correct