답안 #20173

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
20173	2016-03-01T06:10:08 Z	sui	괄호 (kriii4_R)	C++14	8 / 100	127 ms	48604 KB

R

#define _CRT_SECURE_NO_WARNINGS // scanf(), gets() (needed for Visual C++)

//#define NDEBUG
#include <cassert>

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <functional>
#include <string>
#include <vector>

#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <stack>
#include <deque>


using namespace std;

#define MEMSET(x, WITH) memset(x, (WITH), sizeof(x))
#define FOR(i, E) for(int i=0; i<(E); i++)
#define REP(i, LO, HI) for(int i=(LO); i<=(HI); i++)

#define GETINT(x) scanf("%d", &x)
#define GETDBL(x) scanf("%lf", &x)
#define GETSTR(x) scanf("%s", x)
#define NEWINT(x) int x; scanf("%d", &x)
#define NEWDBL(x) double x; scanf("%lf", &x)
#define NEWLN putchar('\n')

typedef long long ll;

const ll MOD = 1000000007;
//const double PI = atan(1) * 4;

#ifdef _WIN32
#define popcnt __popcnt
#else
#define popcnt __builtin_popcount
#endif





const int SZ = 2000333;

ll inv[SZ];
ll fac[SZ];
ll invfac[SZ];

void precalc() {
	inv[1] = 1;
	for (int x=2; x<SZ; x++) {
		ll q = MOD / x;
		ll r = MOD % x;

		q = MOD - q;
		inv[x] = q * inv[r] % MOD;
	}

	fac[0] = 1;
	for (int x=1; x<SZ; x++) fac[x] = fac[x-1] * x % MOD;

	invfac[0] = 1;
	for (int x=1; x<SZ; x++) invfac[x] = invfac[x-1] * inv[x] % MOD;
}

ll getCatalanNumber(int n) {
	return fac[2*n] * invfac[n] % MOD * invfac[n+1] % MOD;
}







int main() {
	precalc();

	int N, K;
	cin >> N >> K;



	ll sum = K;
	ll a = K;
	ll k = K*K%MOD;

	for (int i=2; i<=N; i++) {
		if (i&1) {
			sum = (sum*K%MOD + sum - a + MOD) % MOD;
			a = getCatalanNumber(i/2 + 1) * k % MOD;
			k = k * K % MOD;
		} 
		else {
			sum = (sum*K%MOD + sum) % MOD;
		}
	}


	cout << sum << endl;


	return 0;
}

Subtask #1

8.0 / 8.0

#	결과	실행 시간	메모리	Grader output
1	Correct	116 ms	48604 KB	Output is correct
2	Correct	109 ms	48604 KB	Output is correct
3	Correct	124 ms	48604 KB	Output is correct
4	Correct	112 ms	48604 KB	Output is correct
5	Correct	126 ms	48604 KB	Output is correct
6	Correct	110 ms	48604 KB	Output is correct
7	Correct	114 ms	48604 KB	Output is correct
8	Correct	107 ms	48604 KB	Output is correct
9	Correct	108 ms	48604 KB	Output is correct
10	Correct	113 ms	48604 KB	Output is correct
11	Correct	107 ms	48604 KB	Output is correct
12	Correct	122 ms	48604 KB	Output is correct
13	Correct	123 ms	48604 KB	Output is correct
14	Correct	117 ms	48604 KB	Output is correct
15	Correct	113 ms	48604 KB	Output is correct
16	Correct	110 ms	48604 KB	Output is correct
17	Correct	121 ms	48604 KB	Output is correct
18	Correct	127 ms	48604 KB	Output is correct
19	Correct	123 ms	48604 KB	Output is correct
20	Correct	123 ms	48604 KB	Output is correct

Subtask #2

0.0 / 92.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	115 ms	48604 KB	Output isn't correct
2	Halted	0 ms	0 KB	-