#include <vector>

//From http://www.richelbilderbeek.nl/CppCountDeadEnds.htm
const int CountDeadEnds(const std::vector<std::vector<int> >& maze)
{
  const int size = maze.size();

  int nDeadEnds = 0;

  for (int y=1; y!=size-1; ++y)
  {
    for (int x=1; x!=size-1; ++x)
    {
      if (maze[y][x] != 0) continue; //Continue if here is a wall
      const int nWalls
        = (maze[y+1][x  ] == 1 ? 1 : 0)
        + (maze[y-1][x  ] == 1 ? 1 : 0)
        + (maze[y  ][x+1] == 1 ? 1 : 0)
        + (maze[y  ][x-1] == 1 ? 1 : 0);
      if (nWalls == 3) ++nDeadEnds;

    }
  }
  return nDeadEnds;
}