Shuffle an array with Fisher-Yates shuffle

random_permute.py

Shuffle an array with Fisher-Yates shuffle

""" 
Given input N generate a random permutation of 1 to N.

Example: N=5 Output: 1 5 2 4 3

Based on this post https://www.geeksforgeeks.org/generate-a-random-permutation-of-1-to-n/

"""

import random

def swap(x,m,n):
    temp=x[m]
    x[m] = x[n]
    
    x[n]=temp
    
def rand_perm(N):
    
    x = range(1,N+1)
    #print x
    for i in xrange(N-1, 0, -1):
        j=random.randint(0,i)
        #print i,j
        swap(x,i,j)
    print x
        
    
rand_perm(20)

B