## Introduction

In this article, let’s have a look at Complexity analysis of Data Structure and Algorithms.

Complexity analysis is a technique used to determine the time and space requirements of an algorithm. It involves expressing the run time or space usage of an algorithm as a function of the size of the input, using a notation such as Big O notation.

For example, consider the problem of finding the maximum value in a list of n numbers. One way to solve this problem is to iterate through the list, keeping track of the maximum value seen so far. This algorithm has a time complexity of O(n), because the number of steps required to solve the problem grows linearly with the size of the input.

Time Complexity

Space Complexity

**Time Complexity**

Time complexity is a measure of how long an algorithm takes to run as a function of the size of the input. In other words, it describes how the running time of an algorithm increases as the size of the input increases. For example, if an algorithm has a time complexity of O(n), it means that the running time increases linearly with the size of the input. If an algorithm has a time complexity of O(n^2), it means that the running time increases quadratically with the size of the input. There are many different time complexity classes, such as O(log n), O(n log n), and O(n^2), among others.

The study of time complexity is important because it allows us to compare the efficiency of different algorithms for the same problem. By understanding the time complexity of an algorithm, we can determine which algorithms are likely to be faster for a given problem and which ones are likely to be slower. This can be very useful when trying to choose the right algorithm for a particular task.

When analyzing the time complexity of an algorithm, it is important to consider the worst-case scenario. This means that we look at the maximum amount of time the algorithm will take to run, assuming that the input is the largest and most difficult it could be. This is because the worst-case scenario is the most important one to consider, as it will determine how the algorithm performs in the most challenging situations.

One way to analyze the time complexity of an algorithm is to use the “Big O” notation. This notation allows us to describe the time complexity of an algorithm in a concise way. For example, if an algorithm has a time complexity of O(n^2), it means that the running time is proportional to the square of the size of the input. This means that if the input size doubles, the running time will increase by a factor of four.

These are time complexities of some famous sorting algorithms

Overall, the study of time complexity is an important part of computer science and is essential for understanding the efficiency of algorithms. By understanding the time complexity of an algorithm, we can choose the right algorithm for a particular task and ensure that our programs run efficiently.

**Space Complexity**

Space complexity is a measure of the amount of memory or storage required by an algorithm to solve a problem. It is typically expressed using Big O notation, which gives an upper bound on the amount of space required by the algorithm as a function of the size of the input.

For example, consider the problem of finding the maximum value in a list of n numbers. One way to solve this problem is to iterate through the list, keeping track of the maximum value seen so far. This algorithm has a space complexity of O(1), because it only requires a fixed amount of space to store the maximum value.

On the other hand, consider the problem of finding the maximum value in a list of n numbers using a divide and conquer approach. This algorithm involves dividing the list into two halves, finding the maximum value in each half, and then comparing the two values to determine the overall maximum value. The space complexity of this algorithm is O(n), because it requires additional space to store the two halves of the input list.

These are space complexities of some famous sorting and searching algorithms

In general, space complexity is an important consideration in algorithm design, because it can affect the performance of a program. By choosing algorithms with lower space complexity, we can ensure that our programs will not run out of memory, even on large inputs.

Hurray! Now you have mastered the Complexity analysis of Data Structure and Algorithms. In the next article, we will go deeper into the concepts.

**Happy Coding!**