Submission #949285

#	Time	Username	Problem	Language	Result	Execution time	Memory
949285		mansur	Tents (JOI18_tents)	C++17	100 / 100	112 ms	70840 KiB

tents

//#pragma GCC target( "sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")

#include<bits/stdc++.h>	

using namespace std;

#define all(a) a.begin(), a.end()                                                   
#define rall(a) a.rbegin(), a.rend()                 
#define sz(a) a.size()
#define pf push_front
#define pb push_back
#define vt vector
#define s second
#define f first
#define nl '\n'
 
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
 
vt<pii> rid = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
vt<pii> dir = {{-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
 
const int N = 1e6 + 5, mod = 1e9 + 7;

const ll inf = 1e9;
 
double eps = 1e-15;
                        
bool fl = 0;

void slv() {
	int n, m;
	cin >> n >> m;
	ll dp[n + 1][m + 1];
	for (int i = 0; i <= n; i++) {
		for (int j = 0; j <= m; j++) {
			dp[i][j] = (!i || !j);
		}
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			dp[i][j] = (dp[i - 1][j - 1] * 4 * j) % mod;
			dp[i][j] = (dp[i][j] + dp[i - 1][j]) % mod;
			if (j > 1) dp[i][j] = (dp[i][j] + dp[i - 1][j - 2] * j * (j - 1) / 2) % mod;
			if (i > 1) dp[i][j] = (dp[i][j] + dp[i - 2][j - 1] * j * (i - 1)) % mod;	
		}
	}
	cout << dp[n][m] - 1;
}   
 
int main() {
	//freopen("shops.in", "r", stdin);                                                                                     
	//freopen("shops.out", "w", stdout);                                                                                     
	ios_base::sync_with_stdio(0);                                                                                       
	cin.tie(0);
	int tp = 1;
	if (fl) cin >> tp;
	while (tp--) {
		slv();
	}
}

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