Submission #19300

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19300	2016-02-24T09:08:40 Z	ainta	Σ (kriii4_P2)	C++	100 / 100	4 ms	1084 KB

P2

#include<stdio.h>
#include<algorithm>
using namespace std;
int n;
long long Mod = 1000000007, A, B, C, D, TA, TB;
long long Inv(long long a){
    long long b = Mod - 2, r = 1;
    while(b){
        if(b%2)r=r*a%Mod;
        a=a*a%Mod;b/=2;
    }
    return r;
}
int main(){
    int i;
    scanf("%d",&n);
    A = 1, B = 0;
    for(i=1;i<=n;i++){
        scanf("%lld%lld",&C,&D);
        TB = B*C+A*D;
        TA = A*C;
        TA%=Mod, TB%=Mod;
        A = TA, B = TB;
    }
    printf("%lld\n",B*Inv(A)%Mod);
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	1084 KB	Output is correct
2	Correct	0 ms	1084 KB	Output is correct
3	Correct	0 ms	1084 KB	Output is correct
4	Correct	0 ms	1084 KB	Output is correct
5	Correct	0 ms	1084 KB	Output is correct
6	Correct	4 ms	1084 KB	Output is correct
7	Correct	0 ms	1084 KB	Output is correct
8	Correct	0 ms	1084 KB	Output is correct
9	Correct	0 ms	1084 KB	Output is correct
10	Correct	3 ms	1084 KB	Output is correct
11	Correct	3 ms	1084 KB	Output is correct
12	Correct	3 ms	1084 KB	Output is correct
13	Correct	0 ms	1084 KB	Output is correct
14	Correct	0 ms	1084 KB	Output is correct
15	Correct	3 ms	1084 KB	Output is correct
16	Correct	2 ms	1084 KB	Output is correct
17	Correct	0 ms	1084 KB	Output is correct
18	Correct	3 ms	1084 KB	Output is correct
19	Correct	3 ms	1084 KB	Output is correct
20	Correct	2 ms	1084 KB	Output is correct