Submission #356779

#	Time	Username	Problem	Language	Result	Execution time	Memory
356779		Sparky_09	Tents (JOI18_tents)	C++17	100 / 100	127 ms	71060 KiB

tents

#include "bits/stdc++.h"
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

ll MOD = 1e9+7;
int h, w;
ll dp[3010][3010];

int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
#ifdef LOCAL_DEFINE
	freopen("input.txt", "r", stdin);
#endif
  cin >> h >> w;
  for(int i = 0; i <= w; i++){
  	dp[0][i] = 1; 
  }	
  for(int i = 0; i <= h; i++){
  	dp[i][0] = 1;
  }	
  //memset(dp, 0, sizeof dp);
  for(int i = 1; i <= h; i++){
    for(int j = 1; j <= w; j++){
      dp[i][j] += dp[i-1][j]; 
      dp[i][j] += 4*j*dp[i-1][j-1]; 
      if(j>1) dp[i][j] += j*(j-1)/2*dp[i-1][j-2]; 
      if(i>1) dp[i][j] += j*(i-1)*dp[i-2][j-1];
      dp[i][j] %= MOD;
    }
  }
  cout << dp[h][w]-1 % MOD << endl;
}

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