rotate90_2d_array.py

#!/bin/env python

def generateNdimensionArray(n):
    """
    this function generate a n-dimension array like following
    [[1, 2, 3, 4, 5],
    [6, 7, 8, 9, 10],
    [11, 12, 13, 14, 15],
    [16, 17, 18, 19, 20],
    [21, 22, 23, 24, 25]]
    """
    return [[i+j*n +1  for i in range(n)] for j in range(n)] 

def rotate90_array(a, d):
    """
    this function rotate a n-dimension array like following
    Original array is:
    [[1, 2, 3, 4, 5],
    [6, 7, 8, 9, 10],
    [11, 12, 13, 14, 15],
    [16, 17, 18, 19, 20],
    [21, 22, 23, 24, 25]]
    Rotated 90 clockwise array is:
    [[21, 16, 11, 6, 1],
    [22, 17, 12, 7, 2],
    [23, 18, 13, 8, 3],
    [24, 19, 14, 9, 4],
    [25, 20, 15, 10, 5]]
    """
    for i in range(0, int(d/2)):
        for j in range(i, d-i-1):
            a[i][j], a[d-1-j][i], a[d-1-i][d-1-j], a[j][d-1-i] = \
            a[d-1-j][i], a[d-1-i][d-1-j], a[j][d-1-i], a[i][j]

if __name__ == '__main__':
    n=5
    array = generateNdimensionArray(n)
    print("Original array is:")
    pprint(array)
    rotate90_array(array, len(array))
    from pprint import pprint
    print("Rotated 90 clockwise array is:")
    pprint(array)

Original array is:
[[1, 2, 3, 4, 5],
 [6, 7, 8, 9, 10],
 [11, 12, 13, 14, 15],
 [16, 17, 18, 19, 20],
 [21, 22, 23, 24, 25]]
Rotated 90 clockwise array is:
[[21, 16, 11, 6, 1],
 [22, 17, 12, 7, 2],
 [23, 18, 13, 8, 3],
 [24, 19, 14, 9, 4],
 [25, 20, 15, 10, 5]]