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Rotate Image

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).

You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.

    def rotate(self, matrix: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        
		
        n = len(matrix)
        
		# iterate through matrix
        for i in range(n):
            for j in range(i,n):
			
			    # transpose the matrix, turning rows into columns and vice versa
                matrix[i][j],matrix[j][i] = matrix[j][i],matrix[i][j]
			
			# reverse the resulting rows
            matrix[i].reverse()

Posted by Jamie Meyer 3 months ago

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