Walls and Gates Solution

walls-and-gates-solution.js

var maze = [
  [Infinity, -1, 0, Infinity],
  [Infinity, Infinity, Infinity, -1],
  [Infinity, -1, Infinity, -1],
  [0, -1, Infinity, Infinity]
];

var trackers = [];

maze.forEach((row, y) => {
  row.forEach((column, x) => {
    if(column === 0){
      trackers.push({
        x: x,
        y: y,
        distance: 0
      });
    }
  });
});

function spawnTracker(x, y, distance){
  if(maze[y] && maze[y][x] && maze[y][x] === Infinity){
    maze[y][x] = distance;
    newTrackers.push({
      x: x,
      y: y,
      distance: distance
    });
  }
}

while(trackers.length){
  var newTrackers = [];
  trackers.forEach(tracker => {
    spawnTracker(tracker.x + 1, tracker.y, tracker.distance + 1);
    spawnTracker(tracker.x - 1, tracker.y, tracker.distance + 1);
    spawnTracker(tracker.x, tracker.y + 1, tracker.distance + 1);
    spawnTracker(tracker.x, tracker.y - 1, tracker.distance + 1);
  });
  trackers = newTrackers;
}

maze;