itertools.permutations() in Python - HackerRank Solution

Problem Statement :

itertools.permutations(iterable[, r])

This tool returns successive r length permutations of elements in an iterable.

If r is not specified or is None, then r defaults to the length of the iterable, and all possible full length permutations are generated.

Permutations are printed in a lexicographic sorted order. So, if the input iterable is sorted, the permutation tuples will be produced in a sorted order.

Sample Code

>>> from itertools import permutations

>>> print permutations(['1','2','3'])

<itertools.permutations object at 0x02A45210>

>>> 

>>> print list(permutations(['1','2','3']))

[('1', '2', '3'), ('1', '3', '2'), ('2', '1', '3'), ('2', '3', '1'), ('3', '1', '2'), ('3', '2', '1')]

>>> 

>>> print list(permutations(['1','2','3'],2))

[('1', '2'), ('1', '3'), ('2', '1'), ('2', '3'), ('3', '1'), ('3', '2')]

>>>

>>> print list(permutations('abc',3))

[('a', 'b', 'c'), ('a', 'c', 'b'), ('b', 'a', 'c'), ('b', 'c', 'a'), ('c', 'a', 'b'), ('c', 'b', 'a')]

Task

You are given a string S.

Your task is to print all possible permutations of size k of the string in lexicographic sorted order.

Input Format

A single line containing the space separated string S and the integer value k.

Constraints

0<k<=len(S)

The string contains only UPPERCASE characters.

Output Format

Print the permutations of the string S on separate lines.

Solution:

from itertools import permutations

s,n=input().split()
n=int(n)
vals=list(permutations(s,n))
res=[]
for x in vals:
    res.append(''.join(x))

print('\n'.join(sorted(res)))