Nearest Exit from Entrance in Maze LeetCode solution in JavaScript

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function nearestExit(maze, entrance) {
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  const queue = []; // queue for bfs
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  const empty = ".";
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  const [height, width] = [maze.length, maze[0].length];
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  const tried = [...Array(height)].map(() => Array(width).fill(false));
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  const tryStep = (steps, row, col) => {
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    // don't reuse once it's already been tried
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    if (tried[row][col]) return;
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    tried[row][col] = true;
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    if (maze[row][col] !== empty) return; // blocked? i.e. can't step
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    queue.push([steps, row, col]);
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  };
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  const edges = { right: width - 1, bottom: height - 1, left: 0, top: 0 };
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  const trySteppableDirs = (steps, row, col) => {
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    // try steppable directions
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    if (col < edges.right) tryStep(steps, row, col + 1);
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    if (row < edges.bottom) tryStep(steps, row + 1, col);
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    if (col > edges.left) tryStep(steps, row, col - 1);
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    if (row > edges.top) tryStep(steps, row - 1, col);
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  };
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  let steps = 1,
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    [row, col] = entrance;
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  tried[row][col] = true; // don't reuse the entrance
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  trySteppableDirs(steps, row, col);
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  while (queue.length > 0) {
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    // bfs
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    [steps, row, col] = queue.shift();
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    // path to the edge found?
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    if (col === edges.left || col === edges.right) return steps;
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    if (row === edges.top || row === edges.bottom) return steps;
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    trySteppableDirs(steps + 1, row, col);
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  }
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  // NO path to the edge found
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  return -1;
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}