Submission #82389

#	Time	Username	Problem	Language	Result	Execution time	Memory
82389		Kewo	Tents (JOI18_tents)	C++14	100 / 100	297 ms	71496 KiB

tents

#include <bits/stdc++.h>
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define mid ((x + y) / 2)
#define left (ind * 2)
#define right (ind * 2 + 1)
#define mp make_pair
#define timer ((double)clock() / CLOCKS_PER_SEC)
#define endl "\n"
#define spc " "
#define d1(x) cerr<<#x<<":"<<x<<endl
#define d2(x, y) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<endl
#define d3(x, y, z) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<" "<<#z<<":"<<z<<endl
#define fast_io() ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
using namespace std;

typedef long long int lli;
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<double, double> dd;

const int N = (int)(3e3 + 5);
const int LOG = (int)(20);
const int mod = (int)(1e9 + 7);

lli n, m, dp[N][N];

lli f(lli x, lli y)
{
	lli re = 0;
	if(x < 0 || y < 0)
		return 0;
	if(x == 0 || y == 0)
		return 1;
	if(dp[x][y] != -1)
		return dp[x][y];
	re += f(x - 1, y);
	re += f(x - 1, y - 2) * y * (y - 1) / 2;
	re += f(x - 2, y - 1) * (x - 1) * y;
	re += f(x - 1, y - 1) * 4 * y;
	return dp[x][y] = re % mod;
}

int main()
{
	fast_io();
	// freopen("inp.in", "r", stdin);

	cin >> n >> m;
	memset(dp, -1, sizeof dp);

	cout << f(n, m) - 1;
}

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