Submission #1122764

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122764		SulA	Tents (JOI18_tents)	C++20	100 / 100	117 ms	70928 KiB

tents

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
//#pragma GCC target("popcnt")
using namespace __gnu_pbds;
using namespace std;
using ordered_set = tree<int, null_type, less_equal<>, rb_tree_tag, tree_order_statistics_node_update>;
#define popcount __builtin_popcountll
#define all(a) (a).begin(), (a).end()

const int MOD = 1e9+7;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int h,w; cin >> h >> w;
    long long dp[h+1][w+1] = {};
    for (int i = 0; i <= h; i++) dp[i][0] = 1;
    for (int j = 0; j <= w; j++) dp[0][j] = 1;
    for (int i = 1; i <= h; i++) {
        for (int j = 1; j <= w; j++) {
            dp[i][j] = (dp[i-1][j] + dp[i-1][j-1] * 4*j) % MOD;
            if (i >= 2)
                (dp[i][j] += dp[i-2][j-1] * (i-1) * j % MOD) %= MOD;
            if (j >= 2)
                (dp[i][j] += dp[i-1][j-2] * j * (j-1) / 2) %= MOD;
        }
    }
    cout << (MOD + dp[h][w] - 1) % MOD;
}

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52