fork download
copy 
  1. #include <vector>
  2. #include <string>
  3. #include <algorithm>
  4. #include <iostream>
  5. #include <iomanip>
  6.  
  7. using namespace std;
  8.  
  9. const int N = 5;
  10.  
  11. int b[N][N];
  12. int er = N-1, ec = N-1;
  13.  
  14. int coord(int r, int c) { return r*N+c; }
  15.  
  16. void move()
  17. {
  18.     int olr = er, olc = ec;
  19.     for(bool ok = false;!ok;)
  20.     {
  21.         switch(rand()%4)
  22.         {
  23.         case 0: if (er > 0)   { er--; ok = true; } break;
  24.         case 1: if (ec < N-1) { ec++; ok = true; } break;
  25.         case 2: if (er < N-1) { er++; ok = true; } break;
  26.         case 3: if (ec > 0)   { ec--; ok = true; } break;
  27.         }
  28.     }
  29.     cout << er << " <> " << ec << endl;
  30.     int t = b[olr][olc];
  31.     b[olr][olc] = b[er][ec];
  32.     b[er][ec] = t;
  33. }
  34.  
  35. bool invariant()
  36. {
  37.     const int M = N*N - 1;
  38.     int a[M];
  39.     for(int k = 0, i = 0; i < N; ++i)
  40.         for(int j = 0; j < N; ++j)
  41.             if (b[i][j]) a[k++] = b[i][j];
  42.  
  43.     for(int i = 0; i < M; ++i) cout << a[i] << " "; cout << endl;
  44.  
  45.     int sum = 0;
  46.     for(int i = 0; i < M - 1; ++i)
  47.         for(int j = i+1; j < M; ++j)
  48.             if (a[i] > a[j]) sum++;
  49.  
  50.     sum += er+1;
  51.  
  52.     cout << sum << endl;
  53.     return sum%2 == N%2;
  54. }
  55.  
  56.  
  57.  
  58.  
  59. int main(int argc, char * argv[])
  60. {
  61.     for(int k = 0, i = 0; i < N; ++i)
  62.         for(int j = 0; j < N; ++j)
  63.             b[i][j] = ++k;
  64.     b[N-1][N-1] = 0;
  65.  
  66.     for(;;)
  67.     {
  68.         move();
  69.         if (!invariant())
  70.         {
  71.             cout << "Error!!!!!\n";
  72.             break;
  73.         }
  74.     }
  75. }
  76.  
Success #stdin #stdout 0s 5664KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
4 <> 3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
5
4 <> 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
5
4 <> 3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
5
4 <> 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
5
4 <> 3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
5
3 <> 3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 20 21 22 23 19 24 
8
Error!!!!!
https://ideone.com/Nasgvz
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!