111. Spiral Matrix

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Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]

Output: [1,2,3,6,9,8,7,4,5]

Explanation: The matrix is traversed in a spiral order: 1 -> 2 -> 3 -> 6 -> 9 -> 8 -> 7 -> 4 -> 5.

Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]

Output: [1,2,3,4,8,12,11,10,9,5,6,7]

Explanation: The matrix is traversed in a spiral order: 1 -> 2 -> 3 -> 4 -> 8 -> 12 -> 11 -> 10 -> 9 -> 5 -> 6 -> 7.

Time Complexity

O(m × n)

Space Complexity

O(1)