Submission #19301

#	Time	Username	Problem	Language	Result	Execution time	Memory
19301		cki86201	Σ (kriii4_P2)	C++98	100 / 100	6 ms	1720 KiB

P2

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>

using namespace std;
typedef long long ll;
typedef pair<int, int> Pi;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define sz(x) (int)x.size()
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) x.begin(),x.end()

const ll MOD = 1e9 + 7;

ll pw(ll a,ll b){
	a %= MOD;
	ll res = 1;
	while(b){
		if(b&1)res = (res * a) % MOD;
		a = (a * a) % MOD;
		b >>= 1;
	}
	return res;
}

int main(){
	int m;
	scanf("%d", &m);
	ll a = 0;
	while(m--){
		int x, y;
		scanf("%d%d", &x, &y);
		a = (a + y * pw(x, MOD-2)) % MOD;
	}
	printf("%lld", a);
	return 0;
}

• Subtask 1: 100 / 100