Caesar Cipher Encryptor

Category: Strings

Difficulty: Easy

Description

Given a non-empty string of lowercase letters and a non-negative integer representing a key, write a function that returns a new string obtained by shifting every letter in the input string by k positions in the alphabet, where k is the key.

Note that letters should "wrap" around the alphabet; in other words, the letter z shifted by one returns the letter a.

Sample Input

string = "xyz"
key = 2

Sample Output

"zab"

Optimal Space & Time Complexity

O(n) time | O(n) space - where n is the length of the input string