Submission #1082752

# Submission time Handle Problem Language Result Execution time Memory
1082752 2024-09-01T13:03:00 Z toast12 Tents (JOI18_tents) C++14
100 / 100
211 ms 72596 KB
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

const int MOD = 1e9+7;

vector<vector<bool>> ready;
vector<vector<ll>> dp;

// there are h rows and w columns left
ll solve(int h, int w) {
    if (h < 0 || w < 0)
        return 0;
    if (h == 0 || w == 0)
        return 1;
    if (ready[h][w])
        return dp[h][w];
    ll ans = 0;
    // place nothing
    ans += solve(h-1, w);
    ans %= MOD;
    // place one tent in this row
    // this eliminates one row, one column, and there are 4 different directions the opening can be
    ans += 4*solve(h-1, w-1)*w;
    ans %= MOD;
    // place two tents in this row
    // this eliminates one row, two columns and you can place the two tents in w choose 2 different ways
    ans += solve(h-1, w-2)*(w*(w-1)/2);
    ans %= MOD;
    // place two tents in one column, but one of them is in this row
    // this eliminates two rows, one column and you can choose the column w ways and choose the other row (h-1) ways
    ans += solve(h-2, w-1)*w*(h-1);
    ans %= MOD;
    ready[h][w] = true;
    return dp[h][w] = ans;
}

int main() {
    int h, w;
    cin >> h >> w;
    ready.resize(h+1, vector<bool>(w+1));
    dp.resize(h+1, vector<ll>(w+1));
    cout << (solve(h, w)+MOD-1) % MOD << '\n';
    return 0;   
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 440 KB Output is correct
8 Correct 2 ms 604 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 3 ms 1120 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 440 KB Output is correct
8 Correct 2 ms 604 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 3 ms 1120 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 1 ms 860 KB Output is correct
15 Correct 136 ms 45456 KB Output is correct
16 Correct 3 ms 3224 KB Output is correct
17 Correct 16 ms 10496 KB Output is correct
18 Correct 35 ms 12892 KB Output is correct
19 Correct 178 ms 52828 KB Output is correct
20 Correct 132 ms 42332 KB Output is correct
21 Correct 64 ms 27972 KB Output is correct
22 Correct 85 ms 27576 KB Output is correct
23 Correct 55 ms 15704 KB Output is correct
24 Correct 211 ms 72596 KB Output is correct
25 Correct 148 ms 54008 KB Output is correct
26 Correct 178 ms 61860 KB Output is correct
27 Correct 208 ms 69804 KB Output is correct