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/**
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 * @param {number[][]} matrix
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 * @return {number[]}
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 */
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var spiralOrder = function (matrix) {
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  let [top, bot, left, right, ans] = [
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    0,
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    matrix.length - 1,
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    0,
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    matrix[0].length - 1,
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    [],
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  ];
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  while (top <= bot && left <= right) {
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    for (let j = left; j <= right; j++) {
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      ans.push(matrix[top][j]);
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    }
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    top++;
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    for (let i = top; i <= bot; i++) {
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      ans.push(matrix[i][right]);
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    }
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    right--;
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    if (bot < top || right < left) {
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      break;
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    }
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    for (let j = right; left <= j; j--) {
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      ans.push(matrix[bot][j]);
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    }
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    bot--;
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    for (let i = bot; top <= i; i--) {
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      ans.push(matrix[i][left]);
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    }
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    left++;
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  }
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  return ans;
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};