Submission #1099200

#	Time	Username	Problem	Language	Result	Execution time	Memory
1099200		vjudge1	Rack (eJOI19_rack)	C++17	40 / 100	1 ms	460 KiB

rack

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

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

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

        if(number & 1) result = result * number;

        exponent = exponent * exponent;
        number = number >> 1;
    }

    return result;
}


int make_path(long long seed, int length) 
{
    long long path = 0;
    for (int i = 0; i < length; 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;
    int rows = 1 << height;

    std::vector<int> path(height);
    for (int j = 0; j < height; ++j) {
        path[j] = ((node - 1) >> j) & 1;
    }

    

    long long int leaf = 1;
    long long int set = pow(2, height);
    for (int i : path)
    {
        set = set/2;
        if (i == 1) leaf += set;
    }

    cout << leaf%mod << endl;
    return 0;
}

Compilation message (stderr)

rack.cpp: In function 'int main()':
rack.cpp:42:9: warning: unused variable 'rows' [-Wunused-variable]
   42 |     int rows = 1 << height;
      |         ^~~~
rack.cpp: In function 'int binary_exponentiation(int, int)':
rack.cpp:21:12: warning: 'result' may be used uninitialized in this function [-Wmaybe-uninitialized]
   21 |     return result;
      |            ^~~~~~
rack.cpp: In function 'int make_path(long long int, int)':
rack.cpp:29:73: warning: 'result' may be used uninitialized in this function [-Wmaybe-uninitialized]
   29 |         if (((seed >> i) & 1) == 1) path = (path + binary_exponentiation(2, length - i - 1))%mod;
      |                                                    ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60