Submission #1003931

#	Time	Username	Problem	Language	Result	Execution time	Memory
1003931		AdamGS	Tents (JOI18_tents)	C++17	100 / 100	65 ms	70996 KiB

tents

#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll MOD=1e9+7;
const int LIM=3e3+7;
ll dp[LIM][LIM];
int main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  int h, w;
  cin >> h >> w;
  rep(i, h+1) dp[i][0]=1;
  rep(i, w+1) dp[0][i]=1;
  for(int n=1; n<=h; ++n) for(int m=1; m<=w; ++m) {
    ll a=dp[n-1][m];
    ll b=(dp[n-1][m-1]*4*m)%MOD;
    ll c=0;
    if(m>=2) c=(dp[n-1][m-2]*((m*(m-1)/2)%MOD))%MOD;
    ll d=0;
    if(n>=2) d=(dp[n-2][m-1]*((m*(n-1))%MOD))%MOD;
    dp[n][m]=(a+b+c+d)%MOD;
  }
  ll ans=(dp[h][w]-1+MOD)%MOD;
  cout << ans << '\n';
}

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