Submission #1004035

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004035		ByeWorld	Tents (JOI18_tents)	C++14	100 / 100	113 ms	71032 KiB

tents

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 3e3+10;
const int INF = 1e18+10;
const int LOG = 19;
const int MOD = 1e9+7;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};
int sum(int a, int b){
	return (a+b)%MOD;
}
int mul(int a, int b){
	return (a*b)%MOD;
}
int expo(int a, int b){
	if(b==0) return 1;
	int te = expo(a, b/2); te = mul(te, te);
	return (b%2 ? mul(te, a) : te); 
}
void chsum(int &a, int b){
	a = (a+b)%MOD;
}
void chmul(int &a, int b){
	a = (a*b)%MOD;
}

int h, w;
int dp[MAXN][MAXN];

signed 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 i=0; i<=w; i++) dp[0][i] = 1;

	for(int i=1; i<=h; i++){ // occupied rows
		for(int j=1; j<=w; j++){ // occupied column
			dp[i][j] = dp[i][j-1]; // gk pake column terkiri
			if(i>=2) chsum(dp[i][j], mul(i*(i-1)/2, dp[i-2][j-1]));
			if(j>=2) chsum(dp[i][j], mul(mul(i, j-1), dp[i-1][j-2]));
			chsum(dp[i][j], mul(mul(4, i), dp[i-1][j-1]));
			// cout << i << ' ' << j << ' ' << dp[i][j] << " pp\n";
		}
	}
	cout << (dp[h][w]+MOD-1)%MOD << '\n';
}

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