Submission #899017

#	Time	Username	Problem	Language	Result	Execution time	Memory
899017		vjudge1	"The Lyuboyn" code (IZhO19_lyuboyn)	C++17	19 / 100	18 ms	6488 KiB

lyuboyn

#include <bits/stdc++.h>
using namespace std;

#define all(x) x.begin(), x.end()

const int Z = 10000;

mt19937 rng(time(nullptr));

int n, k, t, s;
string ss;

signed main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> n >> k >> t >> ss;
  if (k%2 == 0) {
    cout << "-1\n";
    return 0;
  }
  
  s = 0;
  while (ss.size() < n) ss = "0"+ss;
  for (int i = 0; i < n; i++) {
    s += (1 << (n-i-1)) * (ss[i] == '1');
  }

  if (n <= 4) {
    for (int zz = 0; zz < Z; zz++) {
      vector<int> ans(1 << n);
      for (int i = 0; i < (1 << n); i++) {
        ans[i] = i;
        if (i == s) swap(ans[0], ans[i]);
      }

      
      bool ok = 0;
      shuffle(ans.begin()+1, ans.end(), rng);
      for (int z = 0; z < Z; z++) {
        int x = -1;
        for (int i = 0; i+1 < (1 << n); i++) {
          if (__builtin_popcount(ans[i] ^ ans[i+1]) != k) {
            x = i;
            break;
          }
        }

        if (x == -1) {
          ok = 1;
          break;
        }

        int y = -1;
        for (int i = x+2; i+1 < (1 << n); i++) {
          if (__builtin_popcount(ans[i] ^ ans[i+1]) != k && 
          __builtin_popcount(ans[x] ^ ans[i]) == k && 
          __builtin_popcount(ans[x+1] ^ ans[i+1]) == k) {
            y = i;
            break;
          }
        }

        if (y == -1) break;

        reverse(ans.begin()+x+1, ans.begin()+y+1);
      }
      
      if (!ok || __builtin_popcount(ans[0] ^ ans.back()) != k) continue;
      else {
        cout << (1 << n) << "\n";
        for (int i = 0; i < (1 << n); i++) {
          for (int j = 0; j < n; j++) {
            if ((ans[i] >> (n-j-1)) & 1) ss[j] = '1';
            else ss[j] = '0';
          }
          cout << ss << "\n";
        }
      }
      return 0;
    }
    cout << "-1\n";
  }
  else {
    vector<int> ans((1 << n), -1);
    vector<bool> vis((1 << n), 0);
    ans[0] = 0;
    vis[0] = 1;
    
    for (int i = 1; i < (1 << n); i++) {
      int x = ans[i-1];

      for (int j = 0; j < n; j++) {
        if (vis[x ^ (1 << j)]) continue;

        ans[i] = x ^ (1 << j);
        vis[x ^ (1 << j)] = 1;
        break;
      }
    }

    cout << (1 << n) << "\n";
    for (int i = 0; i < (1 << n); i++) {
      for (int j = 0; j < n; j++) {
        if ((ans[i] >> (n-j-1)) & 1) ss[j] = '1';
        else ss[j] = '0';
      }
      cout << ss << "\n";
    }
  }
}

Compilation message (stderr)

lyuboyn.cpp: In function 'int main()':
lyuboyn.cpp:23:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   23 |   while (ss.size() < n) ss = "0"+ss;
      |          ~~~~~~~~~~^~~

• Subtask 1: 0 / 0
• Subtask 2: 5 / 5
• Subtask 3: 3 / 3
• Subtask 4: 11 / 11
• Subtask 5: 0 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 31
• Subtask 8: 0 / 17