01 Matrix LeetCode solution in JavaScript

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/**
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 * @param {number[][]} mat
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 * @return {number[][]}
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 */
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var updateMatrix = function (mat) {
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  const rows = mat.length,
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    cols = mat[0].length;
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  if (!rows) return mat;
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  const queue = new Queue();
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  const dist = Array.from({ length: rows }, () =>
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    new Array(cols).fill(Infinity)
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  );
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  for (let i = 0; i < rows; i++) {
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    for (let j = 0; j < cols; j++) {
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      if (!mat[i][j]) {
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        dist[i][j] = 0;
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        queue.enqueue([i, j]);
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      }
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    }
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  }
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  const dirs = [
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    [-1, 0],
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    [1, 0],
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    [0, -1],
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    [0, 1],
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  ];
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  while (!queue.isEmpty()) {
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    const [row, col] = queue.dequeue();
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    for (let i = 0; i < 4; i++) {
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      const nRow = row + dirs[i][0],
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        nCol = col + dirs[i][1];
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      if (nRow < 0 || nCol < 0 || nRow >= rows || nCol >= cols) continue;
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      if (dist[nRow][nCol] > dist[row][col] + 1) {
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        dist[nRow][nCol] = dist[row][col] + 1;
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        queue.enqueue([nRow, nCol]);
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      }
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    }
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  }
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  return dist;
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};