Submission #1100878

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100878		Kirill22	Binary Subsequences (info1cup17_binary)	C++17	12.90 / 100	614 ms	262144 KiB

binary

#include "bits/stdc++.h"

using namespace std;

const int mod = (int) 1e9 + 7;
const int N = (int) 5e3;
int dp[N][N];

int get(int k, int a, int b) {
    if (a < 0 || b < 0) {
        return 0;
    }
    if (k == 1 && a == 0 && b == 0) {
        return 1;
    }
    assert(k == a + b + 1);
    if (dp[a][b] == -1) {
        dp[a][b] = 0;
        dp[a][b] += get(a, a - b - 1, b);
        dp[a][b] += get(b, a, b - a - 1);
        dp[a][b] %= mod;
    }
    return dp[a][b];
}

void solve() {
    int k;
    cin >> k;
    k++;
    int ans = 0;
    for (int j = 0; j < k; j++) {
        ans += get(k, j, k - j - 1);
        ans %= mod;
    }
    cout << ans << '\n';
    cout << -1 << '\n';
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    for (int i = 0; i < N; i++) {
        fill(dp[i], dp[i] + N, -1);
    }
    int t = 1;
    cin >> t;
    while (t--) {
        solve();
    }
}

• Subtask 1: 12.9 / 43
• Subtask 2: 0 / 39
• Subtask 3: 0 / 18