[leetcode] spiral matrix

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

For example,
Given the following matrix:

[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
]
You should return [1,2,3,6,9,8,7,4,5].

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  public List<Integer> (int[][] matrix) { List<Integer> list = new LinkedList<>(); if (matrix.length == 0 || matrix[0].length == 0) { return list; } int n = matrix.length; int m = matrix[0].length; int c = (Math.min(m, n) + 1) / 2; for (int i = 0; i < c; i++) { int lastRow = n - 1 - i; int lastCol = m - 1 - i; if (lastRow == i) { for (int j = i; j <= lastCol; j++) { list.add(matrix[i][j]); } } else if (lastCol == i) { for (int j = i; j <= lastRow; j++) { list.add(matrix[j][i]); } } else { for (int j = i; j < lastCol; j++) { list.add(matrix[i][j]); } for (int j = i; j < lastRow; j++) { list.add(matrix[j][lastCol]); } for (int j = lastCol; j > i; j--) { list.add(matrix[lastRow][j]); } for (int j = lastRow; j > i; j--) { list.add(matrix[j][i]); } } } return list; }