HackerRank 'Left Rotation' Solution

Martin Kysel · May 20, 2019

Short Problem Definition:

A left rotation operation on an array shifts each of the array’s elements 1 unit to the left. For example, if 2 left rotations are performed on array [1,2,3,4,5], then the array would become [3,4,5,1,2].

Arrays: Left Rotation


time complexity is O(N)

space complexity is O(N)


Solutions like this is where python really shines. Simple and straight forward.


import math
import os
import random
import re
import sys

# Complete the rotLeft function below.
def rotLeft(a, d):
    return a[d:] + a[:d]

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    nd = raw_input().split()

    n = int(nd[0])

    d = int(nd[1])

    a = map(int, raw_input().rstrip().split())

    result = rotLeft(a, d)

    fptr.write(' '.join(map(str, result)))


Twitter, Facebook