Hackerrank -itertools.permutations() Solution

itertools.permutations(iterable[, r])

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

If  is not specified or is None, then  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 .
Your task is to print all possible permutations of size  of the string in lexicographic sorted order.

Input Format

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

Constraints

The string contains only UPPERCASE characters.

Output Format

Print the permutations of the string  on separate lines.

Sample Input

HACK 2

Sample Output

AC
AH
AK
CA
CH
CK
HA
HC
HK
KA
KC
KH

Explanation

All possible size  permutations of the string "HACK" are printed in lexicographic sorted order.

Solution in Python

from itertools import permutations
string, length = input().split()
output = ["".join(i) for i in permutations(string,int(length))]
output.sort()
print("\n".join(output))