## DEV Community

Abhishek Chaudhary

Posted on

# Flipping an Image

Given an `n x n` binary matrix `image`, flip the image horizontally, then invert it, and return the resulting image.

To flip an image horizontally means that each row of the image is reversed.

• For example, flipping `[1,1,0]` horizontally results in `[0,1,1]`.

To invert an image means that each `0` is replaced by `1`, and each `1` is replaced by `0`.

• For example, inverting `[0,1,1]` results in `[1,0,0]`.

Example 1:

Input: image = [[1,1,0],[1,0,1],[0,0,0]]
Output: [[1,0,0],[0,1,0],[1,1,1]]
Explanation: First reverse each row: [[0,1,1],[1,0,1],[0,0,0]].
Then, invert the image: [[1,0,0],[0,1,0],[1,1,1]]

Example 2:

Input: image = [[1,1,0,0],[1,0,0,1],[0,1,1,1],[1,0,1,0]]
Output: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]
Explanation: First reverse each row: [[0,0,1,1],[1,0,0,1],[1,1,1,0],[0,1,0,1]].
Then invert the image: [[1,1,0,0],[0,1,1,0],[0,0,0,1],[1,0,1,0]]

Constraints:

• `n == image.length`
• `n == image[i].length`
• `1 <= n <= 20`
• `images[i][j]` is either `0` or `1`.

SOLUTION:

``````import math

class Solution:
def flipAndInvertImage(self, image: List[List[int]]) -> List[List[int]]:
n = len(image)
for j in range(math.ceil(n/2)):
for i in range(n):
image[i][j], image[i][n - j - 1] = 1 - image[i][n - j - 1], 1 - image[i][j]
return image
``````