Skip to Content

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 8 months ago

Related Problems

Given a function fn, return a curried version of that function.

A curried function is a function that accepts fewer or an equal number of parameters as the original function and returns either another curried function or the same value the original function would have returned.

In practical terms, if you called the original function like sum(1,2,3), you would call the curried version like csum(1)(2)(3), csum(1)(2,3), csum(1,2)(3), or csum(1,2,3). All these methods of calling the curried function should return the same value as the original.

Given an object, return a valid JSON string of that object. You may assume the object only inludes strings, integers, arrays, objects, booleans, and null. The returned string should not include extra spaces. The order of keys should be the same as the order returned by Object.keys().

Please solve it without using the built-in JSON.stringify method.

Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.

There is only one repeated number in nums, return this repeated number.

You must solve the problem without modifying the array nums and uses only constant extra space.

The Hamming Distance between two integers is the number of positions at which the corresponding bits are different.

Given two integers x and y, return the Hamming distance between them.