Submission #20175

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
20175	2016-03-01T06:31:00 Z	sui	괄호 (kriii4_R)	C++14	100 / 100	67 ms	17352 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 = 1000333;

ll fac[SZ];
ll inv[SZ/2];
ll invfac[SZ/2];

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;
	ll K;
	cin >> N >> K;



	ll sum = 1;
	ll k = 1;

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

			k = k * K % MOD;
		} 
		else {
			sum = (K + 1) * sum % MOD;
		}
	}



	cout << sum << endl;


	return 0;
}

Subtask #1

8.0 / 8.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	53 ms	17352 KB	Output is correct
2	Correct	54 ms	17352 KB	Output is correct
3	Correct	63 ms	17352 KB	Output is correct
4	Correct	60 ms	17352 KB	Output is correct
5	Correct	64 ms	17352 KB	Output is correct
6	Correct	56 ms	17352 KB	Output is correct
7	Correct	57 ms	17352 KB	Output is correct
8	Correct	57 ms	17352 KB	Output is correct
9	Correct	51 ms	17352 KB	Output is correct
10	Correct	53 ms	17352 KB	Output is correct
11	Correct	56 ms	17352 KB	Output is correct
12	Correct	63 ms	17352 KB	Output is correct
13	Correct	62 ms	17352 KB	Output is correct
14	Correct	57 ms	17352 KB	Output is correct
15	Correct	57 ms	17352 KB	Output is correct
16	Correct	51 ms	17352 KB	Output is correct
17	Correct	62 ms	17352 KB	Output is correct
18	Correct	65 ms	17352 KB	Output is correct
19	Correct	62 ms	17352 KB	Output is correct
20	Correct	58 ms	17352 KB	Output is correct

Subtask #2

92.0 / 92.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	57 ms	17352 KB	Output is correct
2	Correct	55 ms	17352 KB	Output is correct
3	Correct	51 ms	17352 KB	Output is correct
4	Correct	61 ms	17352 KB	Output is correct
5	Correct	61 ms	17352 KB	Output is correct
6	Correct	63 ms	17352 KB	Output is correct
7	Correct	61 ms	17352 KB	Output is correct
8	Correct	49 ms	17352 KB	Output is correct
9	Correct	57 ms	17352 KB	Output is correct
10	Correct	43 ms	17352 KB	Output is correct
11	Correct	56 ms	17352 KB	Output is correct
12	Correct	56 ms	17352 KB	Output is correct
13	Correct	64 ms	17352 KB	Output is correct
14	Correct	50 ms	17352 KB	Output is correct
15	Correct	51 ms	17352 KB	Output is correct
16	Correct	62 ms	17352 KB	Output is correct
17	Correct	54 ms	17352 KB	Output is correct
18	Correct	63 ms	17352 KB	Output is correct
19	Correct	67 ms	17352 KB	Output is correct
20	Correct	63 ms	17352 KB	Output is correct