Write a function

An extra day is added to the calendar almost every four years as February 29, and the day is called a leap day. It corrects the calendar for the fact that our planet takes approximately 365.25 days to orbit the sun. A leap year contains a leap day.

Validating Credit Card Numbers

You and Fredrick are good friends. Yesterday, Fredrick received credit cards from ABCD Bank. He wants to verify whether his credit card numbers are valid or not. You happen to be great at regex so he is asking for your help!

Leetcode SQL

601. Human Traffic of Stadium

Table: Stadium

+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| id            | int     |
| visit_date    | date    |
| people        | int     |
+---------------+---------+
visit_date is…

Set .discard(), .remove() & .pop()

.remove(x)

This operation removes element from the set.
If element does not exist, it raises a KeyError.
The .remove(x) operation returns None.

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:

Iterables and Iterators

The itertools module standardizes a core set of fast, memory efficient tools that are useful by themselves or in combination. Together, they form an iterator algebra making it possible to construct specialized tools succinctly and efficiently in pure Python.

Company Logo

A newly opened multinational brand has decided to base their company logo on the three most common characters in the company name. They are now trying out various combinations of company names and logos based on this condition. Given a string S, which is the company name in lowercase letters, your task…

The Captain’s Room

Mr. Anant Asankhya is the manager at the INFINITE hotel. The hotel has an infinite amount of rooms.

One fine day, a finite number of tourists come to stay at the hotel.
The tourists consist of:
 A Captain.
An unknown group of families consisting of K members per group…

Set Mutations

We have seen the applications of union, intersection, difference and symmetric difference operations, but these operations do not make any changes or mutations to the set.

We can use the following operations to create mutations to a set:

Merge the Tools!

Consider the following:

A string, s, of length n where s = c0 c1 c2…cn-1.
An integer,k , where k is a factor of n.
We can split s into n/k substrings where each subtring, ti, consists of a contiguous block of k characters in s. Then, use each ti to create string ui such…