oj.uz

Submission #355453

# Submission time Handle Problem Language Result Execution time Memory
355453 2021-01-22T13:49:19 Z kostia244 Tents (JOI18_tents) C++17
100 / 100
 210 ms 91884 KB 
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,ssse3")
#include<bits/stdc++.h>
#define all(x) begin(x), end(x)
using namespace std;
const int maxn = 3030, mod = 1e9 + 7;
int n, m, f[maxn][maxn], g[maxn][maxn], h[maxn][maxn], C[maxn][maxn], fact[maxn];
int nck(int n, int k) {
	if(k > n || k < 0) return 0;
	return C[n][k];
}
int calc(int N, int X, int Y) {//N total, X paired, Y single
	int ans = nck(N, X)*1ll*nck(N-X, Y)%mod;
	ans = ans*1ll*f[X][0]%mod;
	return ans;
}
int main() {
	cin.tie(0)->sync_with_stdio(0);
	for(int i = 0; i < maxn; i++)
		for(int j = 0; j <= i; j++)
			if(!j) C[i][j] = 1;
			else C[i][j] = (C[i-1][j] + C[i-1][j-1])%mod;
	fact[0] = 1;
	for(int i = 1; i < maxn; i++) fact[i] = fact[i-1]*1ll*i%mod;
	cin >> n >> m;
	f[0][0] = 1;
	for(int i = 0; i < max(m, n); i++) {
		for(int j = 0; j <= i; j++) {
			(f[i+1][j+1] += f[i][j])%=mod;
			if(j) f[i+1][j-1] = (f[i+1][j-1] + f[i][j]*1ll*j)%mod;
		}
	}
	for(int i = 0; i <= max(m, n); i++) {
		for(int j = 0; j <= max(m, n); j++) {
			if(min(i, j) == 0) h[i][j] = 1;
			else {
				h[i][j] = (h[i-1][j] + h[i-1][j-1]*4ll*j)%mod;
			}
		}
	}
	int ans = mod-1;
	for(int a = 0; a <= max(n, m); a++)
		for(int b = 0; b <= max(n, m); b++) if(n-2*a-b >= 0 && m-2*b-a >= 0) {
			int res = calc(n, 2*a, b)*1ll*calc(m, 2*b, a)%mod;
			res = res*1ll*fact[a]%mod;
			res = res*1ll*fact[b]%mod;
			res = res*1ll*h[n-2*a-b][m-2*b-a]%mod;
			ans = (ans + res)%mod;
		}
	cout << ans << '\n';
}

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 28652 KB Output is correct
2 Correct 24 ms 30188 KB Output is correct
3 Correct 26 ms 28780 KB Output is correct
4 Correct 25 ms 30316 KB Output is correct
5 Correct 25 ms 30828 KB Output is correct
6 Correct 24 ms 30572 KB Output is correct
7 Correct 24 ms 30444 KB Output is correct
8 Correct 25 ms 30956 KB Output is correct
9 Correct 23 ms 29548 KB Output is correct
10 Correct 25 ms 31212 KB Output is correct
11 Correct 25 ms 31340 KB Output is correct
12 Correct 29 ms 31340 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 28652 KB Output is correct
2 Correct 24 ms 30188 KB Output is correct
3 Correct 26 ms 28780 KB Output is correct
4 Correct 25 ms 30316 KB Output is correct
5 Correct 25 ms 30828 KB Output is correct
6 Correct 24 ms 30572 KB Output is correct
7 Correct 24 ms 30444 KB Output is correct
8 Correct 25 ms 30956 KB Output is correct
9 Correct 23 ms 29548 KB Output is correct
10 Correct 25 ms 31212 KB Output is correct
11 Correct 25 ms 31340 KB Output is correct
12 Correct 29 ms 31340 KB Output is correct
13 Correct 61 ms 63084 KB Output is correct
14 Correct 79 ms 75244 KB Output is correct
15 Correct 171 ms 86148 KB Output is correct
16 Correct 51 ms 55168 KB Output is correct
17 Correct 66 ms 62060 KB Output is correct
18 Correct 61 ms 49772 KB Output is correct
19 Correct 175 ms 89708 KB Output is correct
20 Correct 151 ms 78836 KB Output is correct
21 Correct 106 ms 69868 KB Output is correct
22 Correct 107 ms 71788 KB Output is correct
23 Correct 114 ms 91756 KB Output is correct
24 Correct 210 ms 91884 KB Output is correct
25 Correct 166 ms 82028 KB Output is correct
26 Correct 187 ms 87404 KB Output is correct
27 Correct 204 ms 90988 KB Output is correct