Submission #220148

#	Time	Username	Problem	Language	Result	Execution time	Memory
220148		kshitij_sodani	Tents (JOI18_tents)	C++17	100 / 100	211 ms	70776 KiB

tents

#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
#include <cstdio>

using namespace std;
#define pb push_back
#define a first
#define b second
typedef long long int llo;
llo mod=1000000007;
int main(){
	llo n,m;
	cin>>n>>m;
	llo dp[n][m];
	dp[0][0]=5;
	for(llo i=1;i<n;i++){
		dp[i][0]=4*(i+1)+((i+1)*i)/2;
		dp[i][0]+=1;
		dp[i][0]%=mod;
	}
	for(llo j=1;j<m;j++){
		dp[0][j]=4*(j+1)+((j+1)*j)/2;
		dp[0][j]+=1;
		dp[0][j]%=mod;
	}
	for(llo i=1;i<n;i++){
		for(llo j=1;j<m;j++){
			dp[i][j]=4*(j+1)*dp[i-1][j-1];
			dp[i][j]+=dp[i-1][j];
			if(i>1){
				dp[i][j]+=dp[i-2][j-1]*(((j+1)*(i))%mod);
			}
			else{
				dp[i][j]+=(((j+1)*i)%mod);
			}
			if(j>1){
				dp[i][j]+=((((j+1)*j)/2)%mod)*dp[i-1][j-2];
			}
			else{
				dp[i][j]+=((j+1)*j)/2;
			}
			dp[i][j]%=mod;
		}
	}
	/*for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			cout<<dp[i][j]<<" ";
		}
		cout<<endl;
	}*/
	cout<<(dp[n-1][m-1]+mod-1)%mod<<endl;

	return 0;
}

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