Submission #19919

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19919	2016-02-25T07:15:25 Z	xdoju	괄호 (kriii4_R)	C++14	8 / 100	125 ms	1084 KB

R

#include <cstdio>
using namespace std;

const int MOD = 1000000007ll;

int modpow(int r, int n) {
	int ret = 1;
	while (n > 0) {
		if (n % 2 > 0) {
			ret = ((long long)ret * r) % MOD;
		}
		r = ((long long)r * r) % MOD;
		n /= 2;
	}
	return ret;
}

inline int modinv(int n) {
	return modpow(n, MOD - 2);
}

inline int modprod(int a, int b) {
	a = a % MOD;
	b = b % MOD;
	return ((long long)a * b) % MOD;
}

inline int modprod(int a, int b, int c) {
	c = c % MOD;
	return (modprod(a, b) * (long long)c) % MOD;
}

inline int moddiv(int a, int b) {
	return ((long long)a * modinv(b)) % MOD;
}

int cc(int n) {
	int ret = 1;
	for (int k = 2 * n; k > n; --k) {
		ret = modprod(ret, k);
	}
	for (int k = 1; k <= n; ++k) {
		ret = moddiv(ret, k);
	}
	return ret;
}

void proc() {
	int n, k;
	scanf("%d %d", &n, &k);

	if (n % 2 == 0) {
		printf("%d", cc(n / 2));
	}
	else {
		printf("%d", moddiv(cc((n + 1) / 2), 2));
	}
}

int main() {
	proc();
	return 0;
}

Subtask #1

8.0 / 8.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	38 ms	1084 KB	Output is correct
2	Correct	8 ms	1084 KB	Output is correct
3	Correct	92 ms	1084 KB	Output is correct
4	Correct	103 ms	1084 KB	Output is correct
5	Correct	105 ms	1084 KB	Output is correct
6	Correct	58 ms	1084 KB	Output is correct
7	Correct	66 ms	1084 KB	Output is correct
8	Correct	44 ms	1084 KB	Output is correct
9	Correct	18 ms	1084 KB	Output is correct
10	Correct	4 ms	1084 KB	Output is correct
11	Correct	5 ms	1084 KB	Output is correct
12	Correct	94 ms	1084 KB	Output is correct
13	Correct	89 ms	1084 KB	Output is correct
14	Correct	39 ms	1084 KB	Output is correct
15	Correct	42 ms	1084 KB	Output is correct
16	Correct	38 ms	1084 KB	Output is correct
17	Correct	114 ms	1084 KB	Output is correct
18	Correct	118 ms	1084 KB	Output is correct
19	Correct	125 ms	1084 KB	Output is correct
20	Correct	121 ms	1084 KB	Output is correct

Subtask #2

0.0 / 92.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	34 ms	1084 KB	Output isn't correct
2	Halted	0 ms	0 KB	-