leetcode_gym/_problems/rotateImage.md

layout, title, last_solved, category, leetcode_url, status

layout	title	last_solved	category	leetcode_url	status
page	Rotate Image	2020-06-11	matrix	https://leetcode.com/problems/rotate-image/	Solved

{% highlight python %}

''' rotate 90 degree = transpose + flip horizontally https://www.geeksforgeeks.org/rotate-matrix-90-degree-without-using-extra-space-set-2/?ref=rp '''

mat = [ [1,2,3], [4,5,6], [7,8,9] ]

def rotateMatrix(mat):

n = len(mat)

for i in range(n):
    for j in range(i,n):
        tmp = mat[i][j]
        mat[i][j] = mat[j][i]
        mat[j][i] = tmp

for row in mat:
    print(row)


print("after second rotation")

for i in range(n):
    for j in range(n//2):
        tmp = mat[i][j]
        mat[i][j] = mat[i][n-j-1]
        mat[i][n-j-1] = tmp 

for row in mat:
    print(row)


return mat

print(rotateMatrix(mat))

for row in mat:

print(row)

{% endhighlight %}