Discover data structures and algorithms using Python. Gain insights into solving real-world problems and typical interview questions with detailed reviews, explanations, and hands-on coding exercises.

Data structures and algorithms are among the most fundamental concepts of Computer Science. Whether it’s real-world problems you’re trying to solve or the typical coding question asked in an interview, almost every problem requires you to demonstrate a deep understanding of data structures and algorithms. 

This course is a detailed review of some of the most common data structures and algorithms that you’ll see in interviews and your everyday work. With implementation details, thorough explanations, and hands-on coding exercises, you’ll quickly gain the confidence you need to solve any problem, no matter the situation.

Data Structures and Algorithms in Python

In this lesson, we will be considering how to test whether a string is a palindrome in Python. At first, we'll come up with a concise solution that takes extra space, but we'll eventually code a solution that takes a linear amount of time and a constant amount of space.

> A palindrome is a word, number, phrase, or any other sequence of characters that reads the same forward as it does backward. 

Here are some examples of a palindrome:

# Implementation

Let's get started with the implementations. 

## Solution 1  

s = "Was it a cat I saw?"

# Solution uses extra space proportional to size of string "s"
s = ''.join([i for i in s if i.isalnum()]).replace(" ", "").lower()
print(s == s[::-1])

Let's discuss the above one-line solution in parts. So the `[i for i in s if i.isalnum()]` statement returns a list of all the characters which are alphanumeric. This helps us get rid of the question marks, the spaces and every character which is not alphanumeric. The `join` function in the same line then joins the elements from this list into a string which is turned into lowercase via `lower` function. 

Finally, on **line 5**, `s` after modifications on **line 4**, is compared with its reversed form. If they are both equal, `True` is printed on the console otherwise `False` will be printed on to the console. The above solution is very concise, but as it requires extra space, we prefer another solution which will solve the problem in linear time. Let's go!

## Solution 2: The Preferred Solution

In this lesson, you will learn how to determine if a string is a palindrome or not. 

Introduction

Stack

Singly Linked Lists

Circular Linked Lists

Doubly Linked Lists

Arrays

Binary Trees

Binary Search Trees

Binary Search

Recursion

String Processing

Is Palindrome

Implementation

Solution 1