HackerRank Python Solution - Functionals - Validating Email Addresses with a Filter

• You are given an integer N followed by N email addresses. Your task is to print a list containing only valid email addresses in lexicographical order.
• Valid email addresses must follow these rules:
• It must have the username@websitename.extension format type.
• The username can only contain letters, digits, dashes and underscores [a-z],[A-Z],[0-9],[_-].
• The website name can only have letters and digits [a-z],[A-Z],[0-9].
• The extension can only contain letters [a-z],[A-Z].
• The maximum length of the extension is 3.

HackerRank Python Solution - Functionals - Map and Lambda Function

Let's learn some new Python concepts! You have to generate a list of the first Fibonacci numbers, 0 being the first number. Then, apply the map function and a lambda expression to cube each Fibonacci number and print the list.

Concept:

• The map() function applies a function to every member of an iterable and returns the result. It takes two parameters: first, the function that is to be applied, and second, the iterables.
• Let's say you are given a list of names, and you have to print a list that contains the length of each name.

>> print (list(map(len, ['Tina', 'Raj', 'Tom'])))  
[4, 3, 3]  

HackerRank Python Solution - Strings - Merge the Tools!

Consider the following:

• A string, s, of length n where s=c₀c₁...c_n-1.
• An integer, k, where k is a factor of n.

We can split s into n/k substrings where each substring, t_i, consists of a contiguous block of k characters in s. Then, use each t_i to create string u_i such that:

• The characters in u_i are a subsequence of the characters in t_i.
• Any repeat occurrence of a character is removed from the string such that each character in u_i occurs exactly once. In other words, if the character at some index j in t_i occurs at a previous index < j in t_i, then do not include the character in string u_i.

Given s and k, print n/k lines where each line i denotes string u_i.

HackerRank Python Solution - Strings - The Minion Game

• Kevin and Stuart want to play 'The Minion Game'.

Game Rules:

• Both players are given the same string, S.
• Both players have to make substrings using the letters of the string S.
• Stuart has to make words starting with consonants.
• Kevin has to make words starting with vowels.
• The game ends when both players have made all possible substrings.

Scoring:

• A player gets a +1 point for each occurrence of the substring in the string S.

HackerRank Python Solution - Strings - Alphabet Rangoli

• You are given an integer, N. Your task is to print an alphabet rangoli of size N. (Rangoli is a form of Indian folk art based on the creation of patterns.)
• Different sizes of alphabet rangoli are shown below:

#size 3

----c----
--c-b-c--
c-b-a-b-c
--c-b-c--
----c----