Submission #19483

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19483	2016-02-24T13:51:17 Z	nosiar	Σ (kriii4_P2)	C++14	100 / 100	18 ms	1716 KB

P2

#include <iostream>
#include <tuple>
using namespace std;
long long mod = 1000000007;
long long m,n,s;
tuple<long long, long long, long long> extended_gcd(long long a, long long b)
{
    if (b == 0)
        return tuple<long long, long long, long long> { a, 1, 0 };
 
    auto r = extended_gcd(b, a % b);
 
    long long d = get<0>(r);
    long long x = get<1>(r);
    long long y = get<2>(r);
 
    return tuple<long long, long long, long long>{ d, y, x - a/b*y };
}
 
/* a has a (unique) multiplicative inverse iif gcd(a,n)=1 */
long long inverse(long long a)
{
    auto r = extended_gcd(a, mod);
    if (get<0>(r) != 1) return -1;
    return (get<1>(r) + mod) % mod;
}
int main() {
    cin >> m;
    long long ans = 0;
    for(int i = 0; i < m; ++i)
    {
        cin>>n>>s;
        ans = (ans+(s*inverse(n)))%mod;
    }
    cout << ans << endl;
     
    return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	11 ms	1716 KB	Output is correct
2	Correct	12 ms	1716 KB	Output is correct
3	Correct	14 ms	1716 KB	Output is correct
4	Correct	17 ms	1716 KB	Output is correct
5	Correct	17 ms	1716 KB	Output is correct
6	Correct	15 ms	1716 KB	Output is correct
7	Correct	13 ms	1716 KB	Output is correct
8	Correct	18 ms	1716 KB	Output is correct
9	Correct	12 ms	1716 KB	Output is correct
10	Correct	18 ms	1716 KB	Output is correct
11	Correct	17 ms	1716 KB	Output is correct
12	Correct	16 ms	1716 KB	Output is correct
13	Correct	17 ms	1716 KB	Output is correct
14	Correct	18 ms	1716 KB	Output is correct
15	Correct	16 ms	1716 KB	Output is correct
16	Correct	16 ms	1716 KB	Output is correct
17	Correct	17 ms	1716 KB	Output is correct
18	Correct	17 ms	1716 KB	Output is correct
19	Correct	16 ms	1716 KB	Output is correct
20	Correct	18 ms	1716 KB	Output is correct