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48 lines
1.1 KiB
Python
48 lines
1.1 KiB
Python
"""
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48. Rotate Image
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Difficulty: Medium
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https://leetcode.com/problems/rotate-image/
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──────────────────────────────────────────────────
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You are given an n x n 2D matrix representing an image, rotate the
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image by 90 degrees (clockwise).
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You have to rotate the image in-place, which means you have to modify
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the input 2D matrix directly. DO NOT allocate another 2D matrix and do
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the rotation.
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Example 1:
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Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
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Output: [[7,4,1],[8,5,2],[9,6,3]]
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Example 2:
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Input: matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
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Output: [[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]
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Constraints:
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• n == matrix.length == matrix[i].length
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• 1 <= n <= 20
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• -1000 <= matrix[i][j] <= 1000
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"""
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class Solution:
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def rotate(self, matrix: List[List[int]]) -> None:
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n = len(matrix)
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for r in range(n):
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for c in range(r + 1, n):
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matrix[r][c], matrix[c][r] = matrix[c][r], matrix[r][c]
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for r in range(n):
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matrix[r].reverse()
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