oj.uz

Submission #220224

# Submission time Handle Problem Language Result Execution time Memory
220224 2020-04-07T11:20:47 Z atoiz Ruins 3 (JOI20_ruins3) C++14
100 / 100
 494 ms 8960 KB 
/*input
10
5 8 9 13 15 16 17 18 19 20
*/

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

#define FOR(i, a, b) for (int i = a; i <= b; ++i)
#define FORB(i, a, b) for (int i = a; i >= b; --i)

const int MAXN = 607, MOD = 1e9 + 7, HALF = (MOD + 1) / 2;
int N, F[MAXN * 2][MAXN], G[2][MAXN][MAXN], H[MAXN], C[MAXN * 2][MAXN * 2];
bool alive[MAXN * 2];

int add(int x, int y)
{ return x -= ((x += y) >= MOD ? MOD : 0); }

int sub(int x, int y)
{ return x += ((x -= y) < 0 ? MOD : 0); }

int mul(int x, int y)
{ return int(1ll * x * y % MOD); }

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> N;
	FOR(_, 0, N - 1) {
		int x;
		cin >> x;
		alive[x] = 1;
	}

	FOR(i, 0, MAXN) C[i][0] = 1;
	FOR(i, 1, MAXN) FOR(j, 1, i) C[i][j] = add(C[i - 1][j - 1], C[i - 1][j]);

	G[0][0][0] = 1;
	FOR(i, 1, N) {
		FOR(c2, 0, i / 2) FOR(c1, 0, i - 2 * c2) {
			G[i & 1][c1][c2] = 0;
			if (c1 + c2 * 2 <= i - 1) G[i & 1][c1][c2] = add(G[i & 1][c1][c2], mul(HALF, G[(i - 1) & 1][c1][c2]));
			if (c1 > 0) G[i & 1][c1][c2] = add(G[i & 1][c1][c2], mul(G[(i - 1) & 1][c1 - 1][c2], C[c1 + c2 * 2][1]));
			if (c2 > 0) G[i & 1][c1][c2] = add(G[i & 1][c1][c2], mul(G[(i - 1) & 1][c1][c2 - 1], C[c1 + c2 * 2][2]));

			if (c1 + c2 * 2 == i - 1) {
				// cout << "g " << i - 1 << ' ' << c1 << ' ' << c2 << ": " << G[(i - 1) & 1][c1][c2] << endl;
				int c0 = i - c1 - c2;
				int mult = add(c0, mul(c1, HALF));
				H[i] = add(H[i], mul(mult, G[(i - 1) & 1][c1][c2]));
			}
		}
	}
	// FOR(i, 1, N) cout << H[i] << " \n"[i == N];

	F[2 * N + 1][0] = 1;
	int num_dead = 0, num_alive = 0;
	for (int i = 2 * N; i >= 1; --i) {
		for (int j = 0; j <= num_alive + alive[i]; ++j) {
			if (alive[i]) {
				F[i][j] = F[i + 1][j];
				for (int k = 0; k < j; ++k) {
					F[i][j] = add(F[i][j], mul(F[i + 1][k], mul(C[num_alive - k][j - k - 1], H[j - k])));
				}
			} else {
				if (num_dead >= j) continue;
				F[i][j] = mul(F[i + 1][j], j - num_dead);
			}
		}

		if (alive[i]) ++num_alive;
		else ++num_dead;
	}

	cout << F[1][N] << endl;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3200 KB Output is correct
2 Correct 7 ms 3328 KB Output is correct
3 Correct 7 ms 3328 KB Output is correct
4 Correct 7 ms 3328 KB Output is correct
5 Correct 8 ms 3328 KB Output is correct
6 Correct 6 ms 3328 KB Output is correct
7 Correct 7 ms 3328 KB Output is correct
8 Correct 13 ms 3328 KB Output is correct
9 Correct 6 ms 3328 KB Output is correct
10 Correct 7 ms 3328 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3200 KB Output is correct
2 Correct 7 ms 3328 KB Output is correct
3 Correct 7 ms 3328 KB Output is correct
4 Correct 7 ms 3328 KB Output is correct
5 Correct 8 ms 3328 KB Output is correct
6 Correct 6 ms 3328 KB Output is correct
7 Correct 7 ms 3328 KB Output is correct
8 Correct 13 ms 3328 KB Output is correct
9 Correct 6 ms 3328 KB Output is correct
10 Correct 7 ms 3328 KB Output is correct
11 Correct 8 ms 3712 KB Output is correct
12 Correct 7 ms 3712 KB Output is correct
13 Correct 21 ms 3712 KB Output is correct
14 Correct 7 ms 3712 KB Output is correct
15 Correct 7 ms 3712 KB Output is correct
16 Correct 9 ms 3840 KB Output is correct
17 Correct 8 ms 3584 KB Output is correct
18 Correct 8 ms 3712 KB Output is correct
19 Correct 7 ms 3712 KB Output is correct
20 Correct 7 ms 3840 KB Output is correct

Subtask #3
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3200 KB Output is correct
2 Correct 7 ms 3328 KB Output is correct
3 Correct 7 ms 3328 KB Output is correct
4 Correct 7 ms 3328 KB Output is correct
5 Correct 8 ms 3328 KB Output is correct
6 Correct 6 ms 3328 KB Output is correct
7 Correct 7 ms 3328 KB Output is correct
8 Correct 13 ms 3328 KB Output is correct
9 Correct 6 ms 3328 KB Output is correct
10 Correct 7 ms 3328 KB Output is correct
11 Correct 8 ms 3712 KB Output is correct
12 Correct 7 ms 3712 KB Output is correct
13 Correct 21 ms 3712 KB Output is correct
14 Correct 7 ms 3712 KB Output is correct
15 Correct 7 ms 3712 KB Output is correct
16 Correct 9 ms 3840 KB Output is correct
17 Correct 8 ms 3584 KB Output is correct
18 Correct 8 ms 3712 KB Output is correct
19 Correct 7 ms 3712 KB Output is correct
20 Correct 7 ms 3840 KB Output is correct
21 Correct 428 ms 8852 KB Output is correct
22 Correct 455 ms 8928 KB Output is correct
23 Correct 436 ms 8796 KB Output is correct
24 Correct 409 ms 8928 KB Output is correct
25 Correct 430 ms 8184 KB Output is correct
26 Correct 479 ms 8960 KB Output is correct
27 Correct 391 ms 8624 KB Output is correct
28 Correct 397 ms 8928 KB Output is correct
29 Correct 421 ms 7444 KB Output is correct
30 Correct 417 ms 8940 KB Output is correct
31 Correct 385 ms 8836 KB Output is correct
32 Correct 452 ms 8924 KB Output is correct
33 Correct 391 ms 8928 KB Output is correct
34 Correct 469 ms 8928 KB Output is correct
35 Correct 399 ms 8928 KB Output is correct
36 Correct 494 ms 8828 KB Output is correct