Submission #2431947


Source Code Expand

/**
 * File    : C.cpp
 * Author  : Kazune Takahashi
 * Created : 2018-4-28 22:56:15
 * Powered by Visual Studio Code
 */

#include <iostream>
#include <iomanip>   // << fixed << setprecision(xxx)
#include <algorithm> // do { } while ( next_permutation(A, A+xxx) ) ;
#include <vector>
#include <string> // to_string(nnn) // substr(m, n) // stoi(nnn)
#include <complex>
#include <tuple>
#include <queue>
#include <stack>
#include <map> // if (M.find(key) != M.end()) { }
#include <set>
#include <random> // random_device rd; mt19937 mt(rd());
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
using namespace std;

#define DEBUG 0 // change 0 -> 1 if we need debug.

typedef long long ll;

// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

// const int C = 1e6+10;
// const ll M = 1000000007;

const int MAX_SIZE = 1000010;
const long long MOD = 1000000007;

long long inv[MAX_SIZE];
long long fact[MAX_SIZE];
long long factinv[MAX_SIZE];

void init() {
  inv[1] = 1;
  for (int i=2; i<MAX_SIZE; i++) {
    inv[i] = ((MOD - inv[MOD%i]) * (MOD/i))%MOD;
  }
  fact[0] = factinv[0] = 1;
  for (int i=1; i<MAX_SIZE; i++) {
    fact[i] = (i * fact[i-1])%MOD;
    factinv[i] = (inv[i] * factinv[i-1])%MOD;
  }
}

long long C(int n, int k) {
  if (n >=0 && k >= 0 && n-k >= 0) {
    return ((fact[n] * factinv[k])%MOD * factinv[n-k])%MOD;
  }
  return 0;
}

long long power(long long x, long long n) {
  if (n == 0) {
    return 1;
  } else if (n%2 == 1) {
    return (x * power(x, n-1)) % MOD;
  } else {
    long long half = power(x, n/2);
    return (half * half) % MOD;
  }
}

long long gcm(long long a, long long b) {
  if (a < b) {
    return gcm(b, a);
  }
  if (b == 0) return a;
  return gcm(b, a%b);
}

ll N;
ll Ika[200010];

int main()
{
  init();
  cin >> N;
  Ika[0] = Ika[1] = 0;
  if (N == 2)
  {
    cout << 1 << endl;
    return 0;
  }
  for (auto A = 2; A <= N - 1; A++)
  {
    ll x = N - 1 - A;
    if (x >= 0 && A >= 0)
    {
      Ika[A] = ((C(A - 1, N - 1 - A) * fact[x]) % MOD * fact[A]) % MOD;
      if (N < 100)
      {
        cerr << "Ika[" << A << "] = " << Ika[A] << endl;
      }
    }
  }
  ll ans = 0;
  for (ll A = 1; A <= N - 1; A++)
  {
    ans += (A * (Ika[A] + MOD - Ika[A - 1])) % MOD;
    ans %= MOD;
  }
  cout << ans << endl;
}

Submission Info

Submission Time
Task C - Painting Machines
User kazunetakahashi
Language C++14 (GCC 5.4.1)
Score 0
Code Size 2438 Byte
Status WA
Exec Time 51 ms
Memory 25216 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 800
Status
AC × 4
AC × 10
WA × 14
Set Name Test Cases
Sample sample_01.txt, sample_02.txt, sample_03.txt, sample_04.txt
All sample_01.txt, sample_02.txt, sample_03.txt, sample_04.txt, sample_01.txt, sample_02.txt, sample_03.txt, sample_04.txt, subtask_1_01.txt, subtask_1_02.txt, subtask_1_03.txt, subtask_1_04.txt, subtask_1_05.txt, subtask_1_06.txt, subtask_1_07.txt, subtask_1_08.txt, subtask_1_09.txt, subtask_1_10.txt, subtask_1_11.txt, subtask_1_12.txt, subtask_1_13.txt, subtask_1_14.txt, subtask_1_15.txt, subtask_1_16.txt
Case Name Status Exec Time Memory
sample_01.txt AC 38 ms 23680 KB
sample_02.txt AC 38 ms 23680 KB
sample_03.txt AC 38 ms 23680 KB
sample_04.txt AC 40 ms 24448 KB
subtask_1_01.txt AC 38 ms 23680 KB
subtask_1_02.txt WA 50 ms 25216 KB
subtask_1_03.txt WA 48 ms 25216 KB
subtask_1_04.txt WA 48 ms 25216 KB
subtask_1_05.txt WA 44 ms 25216 KB
subtask_1_06.txt WA 42 ms 25216 KB
subtask_1_07.txt WA 43 ms 25216 KB
subtask_1_08.txt AC 39 ms 24320 KB
subtask_1_09.txt WA 42 ms 25216 KB
subtask_1_10.txt WA 44 ms 25216 KB
subtask_1_11.txt WA 47 ms 25216 KB
subtask_1_12.txt WA 51 ms 25216 KB
subtask_1_13.txt WA 51 ms 25216 KB
subtask_1_14.txt WA 51 ms 25216 KB
subtask_1_15.txt WA 51 ms 25216 KB
subtask_1_16.txt WA 51 ms 25216 KB