답안 #19410

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
19410	2016-02-24T11:27:19 Z	ilbbke	Σ (kriii4_P2)	C++	100 / 100	12 ms	1084 KB

P2

#include<stdio.h>
#define M 1000000007
 
int m;
long long ans,a,b;
 
long long back(int x){
    long long t;
    if(x==0) return 1;
    if(x==1) return b;
    if(x==2) return b*b;
    t=back(x/2);
    return x%2?t*t%M*b%M:t*t%M;
}
 
long long f(long long x,long long y){
    long long c;
    while(y)
    {
        c=x%y;
        x=y;
        y=c;
    }
    return x;
}
 
int main()
{
    scanf("%d",&m);
    int i;
    long long x;
    for(i=1;i<=m;i++){
        scanf("%lld %lld",&b,&a);
        x=f(a,b);
        a=a/x; b=b/x;
        x=back(1000000005);
        ans=(ans+(x*a%M))%M;
    }
    printf("%lld",ans);
    return 0;
}

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	1084 KB	Output is correct
2	Correct	10 ms	1084 KB	Output is correct
3	Correct	10 ms	1084 KB	Output is correct
4	Correct	10 ms	1084 KB	Output is correct
5	Correct	11 ms	1084 KB	Output is correct
6	Correct	9 ms	1084 KB	Output is correct
7	Correct	10 ms	1084 KB	Output is correct
8	Correct	7 ms	1084 KB	Output is correct
9	Correct	12 ms	1084 KB	Output is correct
10	Correct	8 ms	1084 KB	Output is correct
11	Correct	8 ms	1084 KB	Output is correct
12	Correct	10 ms	1084 KB	Output is correct
13	Correct	12 ms	1084 KB	Output is correct
14	Correct	10 ms	1084 KB	Output is correct
15	Correct	4 ms	1084 KB	Output is correct
16	Correct	8 ms	1084 KB	Output is correct
17	Correct	8 ms	1084 KB	Output is correct
18	Correct	12 ms	1084 KB	Output is correct
19	Correct	10 ms	1084 KB	Output is correct
20	Correct	10 ms	1084 KB	Output is correct