oj.uz

Submission #899072

# Submission time Handle Problem Language Result Execution time Memory
899072 2024-01-05T12:55:09 Z lovrot Tents (JOI18_tents) C++17
100 / 100
 183 ms 71512 KB 
#include <cstdio> 
#include <cstring> 

using namespace std;

typedef long long ll; 

const int N = 3010; 
const int MOD = 1e9 + 7;

inline int add(int a, int b) {
	if(a + b < MOD) return a + b;
	return a + b - MOD; 
}

inline int mult(int a, int b) {
	return (ll) a * b % MOD;
}

inline int pot(int a, int b) {
	int ret = 1;
	for(; b; b /= 2, a = mult(a, a))
		if(b & 1) ret = mult(ret, a);
	return ret;
}

inline int inv(int a) {
	return pot(a, MOD - 2);
}

int w, h;

int C[N][N], F[N][N];

int f(int a, int b) {
	if(!a || !b) return 1;
	if(F[a][b] != -1) return F[a][b];
	return F[a][b] = add(mult(mult(4, a), f(a - 1, b - 1)), f(a, b - 1)); 
}

int c(int a, int b) {
	if(a == b || !b) return 1;
	if(C[a][b] != -1) return C[a][b];
	return C[a][b] = add(c(a - 1, b), c(a - 1, b - 1));
}

int main() {
	memset(C, -1, sizeof(C));
	memset(F, -1, sizeof(F));

	scanf("%d%d", &h, &w); 

	int ans = MOD - 1;
	for(int n = 0; n <= w && h >= 2 * n; ++n) {	
		int v = c(w, n); 
		for(int i = 0; i < n; ++i) v = mult(v, c(h - 2 * i, 2)); 

		int prod = 1;
		for(int m = 0; m <= h && h >= 2 * n + m && w >= 2 * m + n; ++m) {	
			ans = add(ans, mult(v, mult(mult(c(h - 2 * n, m), prod), f(w - n - 2 * m, h - 2 * n - m))));
			prod = mult(prod, c(w - n - 2 * m, 2));
		}
	}
	printf("%d\n", ans);
	return 0;
}

Compilation message

tents.cpp: In function 'int main()':
tents.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |  scanf("%d%d", &h, &w);
      |  ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 71256 KB Output is correct
2 Correct 9 ms 71260 KB Output is correct
3 Correct 9 ms 71260 KB Output is correct
4 Correct 9 ms 71260 KB Output is correct
5 Correct 9 ms 71260 KB Output is correct
6 Correct 9 ms 71296 KB Output is correct
7 Correct 9 ms 71260 KB Output is correct
8 Correct 9 ms 71260 KB Output is correct
9 Correct 10 ms 71260 KB Output is correct
10 Correct 15 ms 71260 KB Output is correct
11 Correct 8 ms 71280 KB Output is correct
12 Correct 12 ms 71260 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 71256 KB Output is correct
2 Correct 9 ms 71260 KB Output is correct
3 Correct 9 ms 71260 KB Output is correct
4 Correct 9 ms 71260 KB Output is correct
5 Correct 9 ms 71260 KB Output is correct
6 Correct 9 ms 71296 KB Output is correct
7 Correct 9 ms 71260 KB Output is correct
8 Correct 9 ms 71260 KB Output is correct
9 Correct 10 ms 71260 KB Output is correct
10 Correct 15 ms 71260 KB Output is correct
11 Correct 8 ms 71280 KB Output is correct
12 Correct 12 ms 71260 KB Output is correct
13 Correct 9 ms 71256 KB Output is correct
14 Correct 9 ms 71260 KB Output is correct
15 Correct 120 ms 71492 KB Output is correct
16 Correct 13 ms 71256 KB Output is correct
17 Correct 21 ms 71380 KB Output is correct
18 Correct 48 ms 71260 KB Output is correct
19 Correct 152 ms 71492 KB Output is correct
20 Correct 110 ms 71464 KB Output is correct
21 Correct 83 ms 71412 KB Output is correct
22 Correct 77 ms 71448 KB Output is correct
23 Correct 42 ms 71512 KB Output is correct
24 Correct 183 ms 71500 KB Output is correct
25 Correct 146 ms 71476 KB Output is correct
26 Correct 159 ms 71484 KB Output is correct
27 Correct 167 ms 71492 KB Output is correct