oj.uz

Submission #1033965

# Submission time Handle Problem Language Result Execution time Memory
1033965 2024-07-25T08:08:47 Z vjudge1 Tents (JOI18_tents) C++17
100 / 100
 213 ms 71300 KB 
#include <bits/stdc++.h>
#define int long long
#define fi first
#define pll pair<long long, long long>
#define se second
#define isz(a) (int)a.size()
using namespace std;

const long long inf = 1e18;
const int maxn = 3e3 + 5;
const int mod = 1e9 + 7;

int n, m, divi;
int cc[maxn][maxn];

long long binpow(int x, int y){
    long long ans = 1;
    while (y){
        if (y & 1) ans = ans * x % mod;
        x = x * x % mod; y >>= 1;
    }
    return ans;
}

int dp(int i, int j){
    if (i < 0 || j < 0) return 0;
    if (cc[i][j] != -1) return cc[i][j];
    int ans = 0;
    ans += dp(i - 1, j); ans %= mod;
    ans += dp(i - 1, j - 2) * j % mod * (j - 1) % mod * divi % mod; ans %= mod;
    ans += dp(i - 2, j - 1) * j % mod * (i - 1) % mod; ans %= mod;
    ans += dp(i - 1, j - 1) * j % mod * 4 % mod; ans %= mod;
    // cout << ans << endl;
    // cout << i << " " << j << " " << cc[i][j] << endl;
    return cc[i][j] = ans;
}

void solve(){
    cin >> n >> m;
    for (int i = 1; i <= n; ++i){
        for (int j = 1; j <= m; ++j) cc[i][j] = -1;
    }
    divi = binpow(2, mod - 2);
    for (int i = 0; i <= n; ++i) cc[i][0] = 1;
    for (int i = 0; i <= m; ++i) cc[0][i] = 1;
    // cc[1][1] = 4;
    cout << ((dp(n, m) - 1)%mod + mod)%mod << "\n";

}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int t = 1; // cin >> t;
    while (t--){
        solve();
    }
}

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 6492 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 1 ms 6492 KB Output is correct
7 Correct 1 ms 860 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 3 ms 8540 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 3 ms 8540 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 6492 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 1 ms 6492 KB Output is correct
7 Correct 1 ms 860 KB Output is correct
8 Correct 2 ms 6492 KB Output is correct
9 Correct 1 ms 4444 KB Output is correct
10 Correct 3 ms 8540 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 3 ms 8540 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 4 ms 9820 KB Output is correct
15 Correct 138 ms 59752 KB Output is correct
16 Correct 3 ms 6748 KB Output is correct
17 Correct 14 ms 17080 KB Output is correct
18 Correct 52 ms 17316 KB Output is correct
19 Correct 166 ms 64096 KB Output is correct
20 Correct 127 ms 52476 KB Output is correct
21 Correct 73 ms 35676 KB Output is correct
22 Correct 114 ms 38748 KB Output is correct
23 Correct 55 ms 42584 KB Output is correct
24 Correct 202 ms 71300 KB Output is correct
25 Correct 146 ms 61532 KB Output is correct
26 Correct 168 ms 66908 KB Output is correct
27 Correct 213 ms 69416 KB Output is correct