oj.uz

Submission #433189

# Submission time Handle Problem Language Result Execution time Memory
433189 2021-06-19T06:38:30 Z Valaki2 Rack (eJOI19_rack) C++14
100 / 100
 13 ms 8064 KB 
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

const ll mod = 1e9+7;

void solve() {
    ll n, k;
    cin >> n >> k;
    --k;
    vector<ll> powers_of_2_nomodulo(61, 0);
    vector<ll> powers_of_2(1 + n, 0);
    powers_of_2[0] = 1;
    powers_of_2_nomodulo[0] = 1;
    for(ll i = 1; i <= n; ++i) {
        powers_of_2[i] = (powers_of_2[i - 1] * 2) % mod;
    }
    for(ll i = 1; i <= 60; ++i) {
        powers_of_2_nomodulo[i] = powers_of_2_nomodulo[i - 1] * 2;
    }
    vector<bool> bits_of_k(1 + n, false);
    ll max_bit_of_k = 0;
    for(ll i = 0; i <= 60; ++i) {
        if(k & powers_of_2_nomodulo[i]) {
            bits_of_k[i] = true;
            max_bit_of_k = i;
        }
    }
    ll to_add = n - 1;
    ll where_we_are = 0;
    ll answer = 1;
    while(to_add >= 0) {
        if(bits_of_k[where_we_are]) {
            answer = (answer + powers_of_2[to_add]) % mod;
        }
        ++where_we_are;
        --to_add;
    }
    cout << answer << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

Compilation message

rack.cpp: In function 'void solve()':
rack.cpp:23:8: warning: variable 'max_bit_of_k' set but not used [-Wunused-but-set-variable]
   23 |     ll max_bit_of_k = 0;
      |        ^~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct

Subtask #3
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 716 KB Output is correct
15 Correct 13 ms 8064 KB Output is correct