Submission #524491

#	Time	Username	Problem	Language	Result	Execution time	Memory
524491		Pety	Beautiful row (IZhO12_beauty)	C++14	100 / 100	503 ms	205424 KiB

beauty

#include <bits/stdc++.h>
#define ll long long

using namespace std;

const int INF = 1e9;
const int MOD = 1e9 + 7;

int n, v[20], ok[20][20];
short bits[(1 << 20)][20];
long long dp[(1 << 20)][20];

int base2 (int x) {
  int cnt = 0;
  while (x) {
    if (x % 2 == 1)
      cnt++;
    x /= 2;
  }
  return cnt;
}

int base3 (int x) {
  int cnt = 0;
  while (x) {
    if (x % 3 == 1)
      cnt++;
    x /= 3;
  }

  return cnt;
}


int main () 
{
  ios_base::sync_with_stdio(false);
  cin.tie(0); cout.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> v[i];
  }
  for (int i = 0; i < n; i++) 
    for (int j = 0; j < n; j++)
      if (base2(v[i]) == base2(v[j]) || base3(v[i]) == base3(v[j]))
        ok[i][j] = 1;
  for (int i = 1; i < (1 << n); i++) {
    for (int j = 0; j < n; j++)
      if (i & (1 << j))
        bits[i][++bits[i][0]] = j;
  }
  for (int i = 1; i < (1 << n); i++) {
    if (bits[i][0] == 1) {
      dp[i][bits[i][1]] = 1;
      continue;
    }
    for (int j = 1; j <= bits[i][0]; j++)
      for (int k = 1; k <= bits[i][0]; k++)
        if (j != k) {
          int b1 = bits[i][j];
          int b2 = bits[i][k];
          if (ok[b1][b2])
          dp[i][b1] = (dp[i ^ (1 << b1)][b2] + dp[i][b1]);
        }
  }
  long long ans = 0;
  for (int i = 0; i < n; i++)
    ans += dp[(1 << n) - 1][i];  
  cout << ans;
  return 0;
}

• Subtask 1: 100 / 100