Submission #1082753

# Submission time Handle Problem Language Result Execution time Memory
1082753 2024-09-01T13:03:01 Z toast12 Tents (JOI18_tents) C++14
100 / 100
234 ms 72588 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 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 0 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 600 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 2 ms 804 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 2 ms 1116 KB Output is correct
# 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 0 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 600 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 2 ms 804 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 2 ms 1116 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 1 ms 860 KB Output is correct
15 Correct 158 ms 45456 KB Output is correct
16 Correct 3 ms 3164 KB Output is correct
17 Correct 15 ms 10328 KB Output is correct
18 Correct 33 ms 12964 KB Output is correct
19 Correct 155 ms 52792 KB Output is correct
20 Correct 117 ms 42348 KB Output is correct
21 Correct 73 ms 27996 KB Output is correct
22 Correct 74 ms 27740 KB Output is correct
23 Correct 45 ms 15704 KB Output is correct
24 Correct 234 ms 72588 KB Output is correct
25 Correct 154 ms 53848 KB Output is correct
26 Correct 170 ms 61788 KB Output is correct
27 Correct 189 ms 69716 KB Output is correct