Print a given matrix in counter-clock wise spiral form

Given a 2D array, print it in counter-clock wise spiral form. See the following examples.
Examples : 
 

Input:
 1 2 3 4
 5 6 7 8
 9 10 11 12
 13 14 15 16
Output: 
1 5 9 13 14 15 16 12 8 4 3 2 6 10 11 7 

Input:
 1 2 3 4 5 6
 7 8 9 10 11 12
 13 14 15 16 17 18
Output: 
1 7 13 14 15 16 17 18 12 6 5 4 3 2 8 9 10 11 

Explanation : 
 

👁 Image

Below is the implementation : 
 

Output : 
 

1 5 9 13 14 15 16 12 8 4 3 2 6 10 11 7 

Time Complexity : O(mn).

Auxiliary Space: O(1) because constant space has been used

Alternate Implementation : 
 

1 5 9 13 14 15 16 12 8 4 3 2 6 10 11 7 

Time Complexity: O(n²)

Auxiliary Space: O(1), since no extra space has been taken.