Submission #1104028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104028		vjudge1	Rack (eJOI19_rack)	C++17	100 / 100	1 ms	508 KiB

rack

#include <algorithm>
#include <iostream>
#include <bits/stdc++.h>
#include <cmath>

using namespace std;
const long long mod = 1e9+7;

int binary_exponentiation(long long number, long long exponent)
{
    long long result = 1;
    while (exponent > 0) {

        if(exponent & 1) result = (result * number)%mod;

        number = (number * number)%mod;
        exponent >>= 1;
    }

    return result % mod;
}


int make_path(long long seed, int length) 
{
    long long path = 0;
    for (int i = 0; i < min(length, 63); i++) {
        if (((seed >> i) & 1) == 1) path = (path + binary_exponentiation(2, length - i - 1))%mod;
    }
    return path;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    long long int height, node;
    cin >> height >> node;
    cout << (make_path(node - 1, height) + 1)%mod << endl;
    return 0;
}

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