Submission #19620

#	Time	Username	Problem	Language	Result	Execution time	Memory
19620		javelinsman	Σ (kriii4_P2)	C++14	100 / 100	19 ms	1716 KiB

P2

#include<iostream>
#include<algorithm>
using namespace std;

typedef long long ll;
const ll MOD = 1e9+7;
ll go(int x,int y){
    x%=MOD;
    if(y==0) return 1;
    if(y==1) return x;
    if(y%2) return go(x,y-1)*x%MOD;
    ll h = go(x,y/2);
    return h*h%MOD;
}

int main(){
    int m;
    cin>>m;
    ll ans = 0;
    while(m--){
        ll a,b;
        cin>>b>>a;
        ans = (ans + ((a%MOD)*go(b,MOD-2))%MOD)%MOD;
    }
    cout<<ans;
}

• Subtask 1: 100 / 100