Submission #925516

# Submission time Handle Problem Language Result Execution time Memory
925516 2024-02-11T21:56:52 Z NK_ Zapina (COCI20_zapina) C++17
110 / 110
289 ms 600 KB
// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>

using namespace std;

#define nl '\n'
#define pb push_back

template<class T> using V = vector<T>;
using vi = V<int>;

const int MOD = 1e9 + 7;

int main() {
	cin.tie(0)->sync_with_stdio(0);
	
	auto add = [&](int &x, int y) {
		x += y; if (x >= MOD) x -= MOD;
	};

	auto mul = [&](int &x, int y) {
		x = (x * 1LL * y) % MOD;
	};

	auto POW = [&](int a, int p) {
		int ans = 1;
		for(; p; p /= 2, mul(a, a)) if (p & 1) mul(ans, a);
		return ans;
	};

	auto INV = [&](int a) {
		return POW(a, MOD - 2);
	};

	int N; cin >> N;

	vi F = {1}, IF = {1}; for(int i = 1; i <= N; i++) {
		F.pb(F.back()); mul(F.back(), i);
		IF.pb(INV(F.back()));
	}

	auto nCk = [&](int n, int k) { 
		int ways = F[n]; 
		mul(ways, IF[n - k]); mul(ways, IF[k]); 
		return ways; 
	};

	V<vi> dp(N + 1, vi(2)), ndp(N + 1, vi(2)); // dp[index][left][happy] = # of ways

	dp[N][0] = 1;
	for(int i = 1; i <= N; i++) {
		for(int x = 0; x <= N; x++) for(int h = 0; h < 2; h++) if (dp[x][h]) {

			for(int g = 0; g <= x; g++) {
				int nx = x - g, nh = h | (g == i);

				int ways = dp[x][h]; mul(ways, nCk(x, g));

				// cout << i << " " << x << " " << h << " => " << nx << " " << nh << " => " << ways << endl;

				add(ndp[nx][nh], ways);
			}
		}

		dp.swap(ndp);
		ndp = V<vi>(N + 1, vi(2));
	} 

	cout << dp[0][1] << nl;

	exit(0-0);
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 344 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 344 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 137 ms 596 KB Output is correct
18 Correct 2 ms 344 KB Output is correct
19 Correct 31 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 186 ms 492 KB Output is correct
22 Correct 20 ms 348 KB Output is correct
23 Correct 2 ms 460 KB Output is correct
24 Correct 39 ms 344 KB Output is correct
25 Correct 26 ms 344 KB Output is correct
26 Correct 53 ms 488 KB Output is correct
27 Correct 264 ms 592 KB Output is correct
28 Correct 259 ms 496 KB Output is correct
29 Correct 262 ms 496 KB Output is correct
30 Correct 265 ms 348 KB Output is correct
31 Correct 265 ms 344 KB Output is correct
32 Correct 272 ms 500 KB Output is correct
33 Correct 274 ms 492 KB Output is correct
34 Correct 272 ms 600 KB Output is correct
35 Correct 274 ms 344 KB Output is correct
36 Correct 280 ms 492 KB Output is correct
37 Correct 289 ms 500 KB Output is correct