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var spiralMatrix = function (m, n, head) {
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  var matrix = new Array(m).fill().map(() => new Array(n).fill(-1));
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  var row = 0,
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    col = 0;
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  var direction = "right";
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  while (head) {
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    matrix[row][col] = head.val;
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    if (direction == "right") {
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      if (col + 1 == n || matrix[row][col + 1] != -1) {
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        direction = "down";
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        row++;
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      } else col++;
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    } else if (direction == "down") {
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      if (row + 1 == m || matrix[row + 1][col] != -1) {
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        direction = "left";
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        col--;
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      } else row++;
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    } else if (direction == "left") {
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      if (col == 0 || matrix[row][col - 1] != -1) {
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        direction = "up";
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        row--;
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      } else col--;
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    } else if (direction == "up") {
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      if (row == 0 || matrix[row - 1][col] != -1) {
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        direction = "right";
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        col++;
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      } else row--;
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    }
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    head = head.next;
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  }
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  return matrix;
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};