## WHAT IS DATA STRUCTURES AND ALGORITHMS?

A data structure is a named locatiaon where data and information are stored and organised based on the associated operations in order to increase the efficiency of programming. Algorithms consist of ordered steps to solve a particular problem or achieve a goal. Learning data structures and their algorithms is essential to create clean and optimised code.

ROADMAP TO LEARNING DATA STRUCTURES AND ALGORITHMS

Let’s learn the steps to acing DSA in detail.

## CHOOSING A LANGUAGE

The choice of a programming language solely depends on your priorities. Most people choose either C, C++, Python or Java. Each of them have their fair share of pros and cons. The following 5 factors can help you determine which programming language will suit your needs the best:

Purpose of Learning — Why do you want to learn DSA? Is it for competitive programming, creating projects or cracking interviews?

Career Goals — Are you aiming to learn DSA for a particular company’s interview? Talk to the employees and get to know what language is preferred there and which will help you score better.

Ease and Comfortability — You might have been programming for long using one language. Being comfortable and knowing the syntax at the back of your hand might make this a better option. If you think you can code easily and efficiently using this language, go for it as long as other factors go well with it.

Usage — This is an important factor to take care of. Determine how commonly a language is used. Usually, people prefer C, C++, Java and Python for DSA. There are other languages too, and there is no harm in using them. However, avoid using languages that are no longer in use.

High Level or Low Level — The choice of the level of language is based on your application.

## GETTING STARTED WITH THE BASICS

Whichever language that you select, you need to be thorough with the syntax and know the data structures that the language provides. There are several primitive and non-primitive data structures that you should be aware of and learn how to code them.

Source: TutorialLink

Learning and mastering these isn’t as tough as it seems to be. You need to strengthen your logic and not mug up the code as it is. Follow the 3 steps to be stronger at your fundamentals:

Read

Visualise by drawing

Understand and Code

Often people think drawing and paper-pen practice as a waste of time but when you learn data structures, this tends to be the best way to strengthen logic. You might have to spend a lot of time solving problems during the first few days. However, it will seem much easier once you get used to solving similar problems.

One of the most common applications of data structures is Search and Sort algorithms. These come in handy not only in programming but even in day-to-day life. The most commonly used of these are:

Binary Search

Search an element in a sorted and rotated array

Bubble Sort

Selection Sort

Insertion Sort

Merge Sort

Heap Sort (Binary Heap)

Quick Sort

Topological Sort

## ALGORITHMS YOU SHOULD KNOW AND MASTER

## MAKING CODE EFFICIENT

Every problem can be solved in various ways. So how do we analyze and select the best solution to a problem? Here is where time and space complexity plays an important role. The time complexity of an algorithm determines the amount of time taken by an algorithm to run. Similarly, the Space complexity of an algorithm specifies the amount of space or memory taken by an algorithm to run.

Understanding the Big-O Notation helps understand us this quantitative measure in a much better way. Here are a few O notations to understand time complexity better. Imagine a class of n students and give a coin to one person randomly. The task is to find who has the coin.

O(1) — It has been found that the coin is with one among 8 students in the classroom. Going and asking individually will consist of 8 questions. Since the number is a constant, the time complexity is O(1).

O(n) — To find who among the entire class of n students has the coin, going and asking them individually is O(n).

O(n.logn) — Divide the class into two groups, then ask: “Is it on the left side, or the right side of the classroom?” Then divide it into two and ask again, and so on. Repeat the process till you are left with one student who has the coin. This is what you mean by O(log n).

O(n²) — You go and ask the first person of the class, if they have the coin and if they know who among the others have a coin. This is what we call O(n²).

Each assignment statement, return statement is counted as 1 unit. Find the cost of each statement, the repetition and then find a total number of units. In the below example, 4n+4 = O(n).

Source: BTechSmartClass

The following table consists of the complexities of the common data structures and algorithms.

Source: HackerEarth

The precedence of time complexity is as follows:

Source: CSharpCorner

DSA IN EVERYDAY LIFE

The first and foremost question that we ask before learning something new — Will it even help us in everyday life? Concepts used in DSA do help you in various everyday tasks as shown below.

## TIPS TO ACCELERATE YOUR JOURNEY IN DSA

Understand the fundamentals of the language that you are programming in. Learn beyond the theory by implementing all concepts in different ways.

Understand the depth of time and space complexity. Code and test.

Focus on strengthening logic instead of studying existing codes. A better logic will help you solve more unseen questions.

Improve problem-solving skills not only specific to programming. It changes the way you think and can help you gain more exposure to larger problems.

Practice coding on sites like Leetcode, GeeksForGeeks, CodeChef, HackerRank, HackerEarth, CodeForces, etc. While practising, ensure that you solve at different difficulty levels. Do not stick to a particular level and solve all from that only. This will reduce your exposure to higher difficulty questions.

Keep calm and believe in yourself. No question is unsolvable.

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