제출 #529119

#	제출 시각UTC-0	아이디	문제	언어	결과	실행 시간	메모리
529119	2022-02-22 07:32:26	fhvirus	Tents (JOI18_tents)	C++17	100 / 100	44 ms	35476 KiB

tents

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#include <bits/stdc++.h>
using namespace std;
const int kN = 3003;
const int MOD = 1e9 + 7;
int H, W;
int dp[kN][kN];
int main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  cin >> H >> W;
  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) {
      int64_t v = dp[i - 1][j];
      v += 4ll * j * dp[i - 1][j - 1];
      if (i >= 2) v += 1ll * dp[i - 2][j - 1] * (i - 1) * j;
      if (j >= 2) v += 1ll * dp[i - 1][j - 2] * j * (j - 1) / 2;
      dp[i][j] = v % MOD;
    }
  cout << (dp[H][W] + MOD - 1) % MOD << '\n';
  return 0;
}
 
 
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• Subtask 1: 48 / 48
• Subtask 2: 52 / 52