Submission #19586

#	Time	Username	Problem	Language	Result	Execution time	Memory
19586		gs12117	Σ (kriii4_P2)	C++98	100 / 100	16 ms	1084 KiB

P2

#include<stdio.h>
int mod=1000000007;
long long int f(long long int x,long long int y){
	if(y==0)return 1;
	long long int r=f(x,y/2);
	r*=r;
	r%=mod;
	if(y%2==0)return r;
	r*=x;
	r%=mod;
	return r;
}
int main(){
	int n,i,a,b;
	long long int res=0;
	scanf("%d",&n);
	for(i=0;i<n;i++){
		scanf("%d%d",&a,&b);
		res+=b*f(a,mod-2)%mod;
		res%=mod;
	}
	printf("%lld\n",res);
}

• Subtask 1: 100 / 100