oj.uz

Submission #892701

# Submission time Handle Problem Language Result Execution time Memory
892701 2023-12-25T17:24:59 Z box Tents (JOI18_tents) C++17
48 / 100
 2000 ms 19116 KB 
#include <bits/stdc++.h>
using namespace std;

#define ar array
#define sz(v) int(std::size(v))
using i64 = long long;

const int N = 3000;
const i64 MOD = 1e9 + 7;

int h, w;
int take[N + 1][N + 1];
i64 roll[N + 1];
i64 fac[N + 1], ifac[N + 1], p4[N + 1];

i64 inv(i64 a) {
    return a == 1 ? 1 : inv(MOD % a) * (MOD - MOD / a) % MOD;
}

i64 nck(int n, int k) {
    if (n < k || k < 0) return 0;
    return fac[n] * ifac[k] % MOD * ifac[n - k] % MOD;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    roll[1] = 1;
    for (int i = 3; i <= N; i += 2) roll[i] = roll[i - 2] * i % MOD;
    fac[0] = ifac[0] = 1;
    for (int i = 1; i <= N; i++) fac[i] = fac[i - 1] * i % MOD, ifac[i] = inv(fac[i]);
    p4[0] = 1;
    for (int i = 1; i <= N; i++) p4[i] = p4[i - 1] * 4 % MOD;
    for (int k = 0; k <= N / 2; k++) for (int n = 0; n <= N; n++)
        take[k][n] = nck(n, k * 2) * (!k ? 1 : roll[k * 2 - 1]) % MOD;
    cin >> h >> w;
    i64 ans = 0;
    for (int x = 0; x <= w; x++) for (int y = 0; y <= h; y++) for (int z = 0; z <= min(w, h); z++) {
        i64 num = nck(w, x) * take[x][h] % MOD
             * nck(h - 2 * x, y) % MOD * take[y][w - x] % MOD
             * fac[x] % MOD * fac[y] % MOD
             * nck(w - x - 2 * y, z) % MOD * nck(h - 2 * x - y, z) % MOD * fac[z] % MOD * p4[z] % MOD;
        ans = (ans + num) % MOD;
    }
    ans += MOD - 1;
    ans %= MOD;
    cout << ans << '\n';
}

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 19036 KB Output is correct
2 Correct 18 ms 19036 KB Output is correct
3 Correct 19 ms 19092 KB Output is correct
4 Correct 18 ms 19036 KB Output is correct
5 Correct 28 ms 19108 KB Output is correct
6 Correct 49 ms 19100 KB Output is correct
7 Correct 35 ms 19036 KB Output is correct
8 Correct 36 ms 19036 KB Output is correct
9 Correct 17 ms 19032 KB Output is correct
10 Correct 97 ms 19096 KB Output is correct
11 Correct 18 ms 19116 KB Output is correct
12 Correct 265 ms 19036 KB Output is correct

Subtask #2
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 19036 KB Output is correct
2 Correct 18 ms 19036 KB Output is correct
3 Correct 19 ms 19092 KB Output is correct
4 Correct 18 ms 19036 KB Output is correct
5 Correct 28 ms 19108 KB Output is correct
6 Correct 49 ms 19100 KB Output is correct
7 Correct 35 ms 19036 KB Output is correct
8 Correct 36 ms 19036 KB Output is correct
9 Correct 17 ms 19032 KB Output is correct
10 Correct 97 ms 19096 KB Output is correct
11 Correct 18 ms 19116 KB Output is correct
12 Correct 265 ms 19036 KB Output is correct
13 Correct 18 ms 19036 KB Output is correct
14 Correct 19 ms 19088 KB Output is correct
15 Execution timed out 2037 ms 19036 KB Time limit exceeded
16 Halted 0 ms 0 KB -