Submission #19325

#	Time	Username	Problem	Language	Result	Execution time	Memory
19325		gs14004	Σ (kriii4_P2)	C++14	100 / 100	17 ms	1720 KiB

P2

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <functional>
#include <vector>
#include <numeric>
#include <deque>
#include <utility>
#include <bitset>
#include <assert.h>
#include <iostream>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;
const int mod = 1e9 + 7;

lint ipow(lint x, lint p){
	lint ret = 1, piv = x % mod;
	while(p){
		if(p&1) ret *= piv;
		piv *= piv;
		ret %= mod;
		piv %= mod;
		p >>= 1;
	}
	return ret;
}

int main(){
	int n;
	lint ret = 0;
	cin >> n;
	for(int i=0; i<n; i++){
		lint a, b;
		cin >> b >> a;
		ret += a * ipow(b, mod - 2) % mod;
		ret %= mod;
	}
	cout << ret;
}

• Subtask 1: 100 / 100