Submission #822407

#	Time	Username	Problem	Language	Result	Execution time	Memory
822407		irmuun	Tents (JOI18_tents)	C++17	100 / 100	152 ms	70792 KiB

tents

#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const ll mod=1e9+7;

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll h,w;
    cin>>h>>w;
    ll dp[h+1][w+1];
    for(ll i=0;i<=h;i++){
        for(ll j=0;j<=w;j++){
            if(i==0||j==0){
                dp[i][j]=1;
                continue;
            }
            dp[i][j]=(dp[i][j-1]+dp[i-1][j-1]*4*i)%mod;
            if(i>=2){
                dp[i][j]+=dp[i-2][j-1]*i*(i-1)/2;
                dp[i][j]%=mod;
            }
            if(j>=2){
                dp[i][j]+=dp[i-1][j-2]*i*(j-1);
                dp[i][j]%=mod;
            }
        }
    }
    cout<<(dp[h][w]-1+mod)%mod;
}

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