Submission #453240

#	Time	Username	Problem	Language	Result	Execution time	Memory
453240		myvaluska	Rack (eJOI19_rack)	C++14	100 / 100	118 ms	288 KiB

rack

#include <iostream>
#include <vector>
#include <string>
#include <set>
#include <cmath>
#include <tuple>
using namespace std;
/*long long int power(long long int n, int k)
{
    long long int vys = 1;
    for (int i = 0; i < k; i++)
    {
        vys = (vys * (n - i)) / (i + 1);
    }
    return vys;
}*/
long long int power(long long int b, long long int p, long long int mod)
{
    long long int vys = 1;
    for (long long int i = 0; i < p; i++)
    {
        vys = vys * b;
        vys %= mod;
    }
    return vys;
}
int main()
{
    /*for (int i = 0; i < 10; i++)
    {
        std::cout << "Hello Flash!\n";
    }*/
    long long int n;
    long long int k;
    cin >> n;
    cin >> k;
    const long long int mod = 1e9 + 7;
    k -= 1;
    long long int i = n - 1;
    long long int vys = 1;
    while (i >= 0)
    {
        if (k % 2 !=0)
        {
            vys = (vys + power(2, i, mod)) % mod;
        }
        k = k / 2;
        i -= 1;
    }
    cout << vys % mod << endl;
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 60 / 60