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Submission #246139

# Submission time Handle Problem Language Result Execution time Memory
246139 2020-07-08T09:31:14 Z proma Rack (eJOI19_rack) C++17
100 / 100
 6 ms 384 KB 
#include <bits/stdc++.h>
#define endl "\n"
#define int long long
#define see(x) cerr<<#x<<"="<<x<<endl;

using namespace std;

const int N = 1e6 + 10;
const int MOD = 1e9 + 7;

int bp (int n) {
    if (!n) return 1;
    if (n & 1) return 2ll * bp(n-1) % MOD;
    int b = bp(n>>1);
    return b * b % MOD;
}

int n, k, ans = 1;

int32_t main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> k;
    k --;

    for (int i = n - 1; i >= 0; -- i)
        if (k & 1) {
            ans += bp(i);
            ans %= MOD;
            k >>= 1;
        }
        else k >>= 1;

    cout << ans << endl;

    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 4 ms 384 KB Output is correct

Subtask #3
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 384 KB Output is correct
10 Correct 4 ms 384 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 5 ms 384 KB Output is correct
13 Correct 5 ms 384 KB Output is correct
14 Correct 5 ms 384 KB Output is correct
15 Correct 6 ms 384 KB Output is correct