Submission #2382368

---

Source Code Expand

# include <bits/stdc++.h>

# define x first    
# define y second
# define mp make_pair
// everything go according to my plan      
# define pb push_back
# define sz(a) (int)(a.size())
# define vec vector         
// shimkenttin kyzdary, dzyn, dzyn, dzyn...
# define y1    Y_U_NO_y1
# define left  Y_U_NO_left
# define right Y_U_NO_right  

using namespace std;

typedef pair <int, int> pii; 
typedef long long ll;
typedef long double ld;

const int Mod = (int)1e9 + 7;
const int MX = 1073741822;
const ll MXLL = 4e18;
const int Sz = 1110111;
// a pinch of soul
inline void Read_rap () {
  ios_base :: sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
}
inline void randomizer3000 () {
  unsigned int seed;
  asm ("rdtsc" : "=A"(seed));
  srand (seed);
}
void files (string problem) {   
  if (fopen ((problem + ".in").c_str(),"r")) {
    freopen ((problem + ".in").c_str(),"r",stdin);
    freopen ((problem + ".out").c_str(),"w",stdout);
  }
}
void localInput(const char in[] = "s") { 
  if (fopen (in, "r")) {
    freopen (in, "r", stdin);
  }
  else
    cerr << "Warning: Input file not found" << endl;
}     
const int N = 4000 + 1;
            
ll dp[N][N], D[N][N];

int n, k;
                 
int main()
{
  # ifdef Local
    //localInput();
  # endif
  Read_rap();
  cin >> n >> k;                         
   
  dp[0][0] = dp[1][0] = 1;
  for (int i = 2; i <= 2*n; i++) {
    for (int j = 0; 2*j <= i; j++)
      dp[i][j] = (dp[i - 1][j] + (i >= 2 && j >= 1 ? dp[i - 2][j - 1] : 0)) % Mod;
  }              
  int m = 2*k;
  D[0][0] = 1;        
  for (int i = 1; i <= m; i++) {
    int len = (n - (i + 1) / 2) / k + 1; 
    for (int s = n; s >= 0; s--) {
      for (int j = 0; j <= s; j++) {
        D[i][s] = (D[i - 1][s - j] * dp[len][j] + D[i][s]) % Mod;
      }
    }            
  }                     
  vec<int> f (n + 1);
  f[0] = 1;
  for (int i = 1; i <= n; i++)
    f[i] = (f[i - 1] * 1ll * i) % Mod;
  
  int ans = 0;

  for (int cnt = 0; cnt <= n; cnt++) {
    int val = ((cnt & 1) ? -1 : +1) *  D[m][cnt] * f[n - cnt] % Mod;
    ans += val;

    if (ans < 0)
      ans += Mod;
    if (ans >= Mod)
      ans -= Mod;
  }
  cout << ans;  

  return 0;
}






// Coded by Z..

Submission Info

Compile Error

./Main.cpp: In function ‘void files(std::string)’:
./Main.cpp:37:50: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
     freopen ((problem + ".in").c_str(),"r",stdin);
                                                  ^
./Main.cpp:38:52: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
     freopen ((problem + ".out").c_str(),"w",stdout);
                                                    ^
./Main.cpp: In function ‘void localInput(const char*)’:
./Main.cpp:43:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
     freopen (in, "r", stdin);
                             ^

Judge Result