What is an Algorithm? Algorithm Basics
Therefore Algorithm refers to a sequence of finite steps to solve a particular problem. Algorithms can be simple and complex depending on what you want to achieve. It can be understood by taking the example of cooking a new recipe. To cook a new recipe, one reads the instructions and steps and executes them one by one, in the given sequence. The result thus obtained is the new dish is cooked perfectly. Every time you use your phone, computer, laptop, or calculator you are using Algorithms. Similarly, algorithms help to do a task in programming to get the expected output. The Algorithm designed are language-independent, i.e. they are just plain instructions that can be implemented in any language, and yet the output will be the same, as expected. What are the Characteristics of an Algorithm?As one would not follow any written instructions to cook the recipe, but only the standard one. Similarly, not all written instructions for programming is an algorithms. In order for some instructions to be an algorithm, it must have the following characteristics:
Properties of Algorithm:
Types of Algorithms:There are several types of algorithms available. Some important algorithms are: 1. Brute Force Algorithm: It is the simplest approach for a problem. A brute force algorithm is the first approach that comes to finding when we see a problem. 2. Recursive Algorithm: A recursive algorithm is based on recursion. In this case, a problem is broken into several sub-parts and called the same function again and again. 3. Backtracking Algorithm: The backtracking algorithm basically builds the solution by searching among all possible solutions. Using this algorithm, we keep on building the solution following criteria. Whenever a solution fails we trace back to the failure point and build on the next solution and continue this process till we find the solution or all possible solutions are looked after. 4. Searching Algorithm: Searching algorithms are the ones that are used for searching elements or groups of elements from a particular data structure. They can be of different types based on their approach or the data structure in which the element should be found. 5. Sorting Algorithm: Sorting is arranging a group of data in a particular manner according to the requirement. The algorithms which help in performing this function are called sorting algorithms. Generally sorting algorithms are used to sort groups of data in an increasing or decreasing manner. 6. Hashing Algorithm: Hashing algorithms work similarly to the searching algorithm. But they contain an index with a key ID. In hashing, a key is assigned to specific data. 7. Divide and Conquer Algorithm: This algorithm breaks a problem into sub-problems, solves a single sub-problem and merges the solutions together to get the final solution. It consists of the following three steps:
8. Greedy Algorithm: In this type of algorithm the solution is built part by part. The solution of the next part is built based on the immediate benefit of the next part. The one solution giving the most benefit will be chosen as the solution for the next part. 9. Dynamic Programming Algorithm: This algorithm uses the concept of using the already found solution to avoid repetitive calculation of the same part of the problem. It divides the problem into smaller overlapping subproblems and solves them. 10. Randomized Algorithm: In the randomized algorithm we use a random number so it gives immediate benefit. The random number helps in deciding the expected outcome. To learn more about the types of algorithms refer to the article about “Types of Algorithms“. Advantages of Algorithms:
Disadvantages of Algorithms:
How to Design an Algorithm?In order to write an algorithm, the following things are needed as a pre-requisite:
Then the algorithm is written with the help of the above parameters such that it solves the problem.
Program: C++
C
Java
Python3
Output Enter the 1st number: 0 Enter the 2nd number: 0 Enter the 3rd number: -1577141152 Sum of the 3 numbers is: -1577141152 One problem, many solutions: The solution to an algorithm can be or cannot be more than one. It means that while implementing the algorithm, there can be more than one method to implement it. For example, in the above problem to add 3 numbers, the sum can be calculated in many ways like:
How to analyze an Algorithm?For a standard algorithm to be good, it must be efficient. Hence the efficiency of an algorithm must be checked and maintained. It can be in two stages:
What is Algorithm complexity and how to find it?An algorithm is defined as complex based on the amount of Space and Time it consumes. Hence the Complexity of an algorithm refers to the measure of the Time that it will need to execute and get the expected output, and the Space it will need to store all the data
(input, temporary data and output). Hence these two factors define the efficiency of an algorithm.
Therefore the complexity of an algorithm can be divided into two types: 1. Space Complexity: The space complexity of an algorithm refers to the amount of memory required by the algorithm to store the variables and get the result. This can be for inputs, temporary operations, or outputs. How to calculate Space
Complexity?
Example: Consider the below algorithm for Linear Search
2. Time Complexity: The time complexity of an algorithm refers to the amount of time that is required by the algorithm to execute and get the result. This can be for normal operations, conditional if-else statements, loop statements, etc. How to calculate Time Complexity?
Example: In the algorithm of Linear Search above, the time complexity is calculated as follows:
How to express an Algorithm?
Is a set of instructions that are designed to perform a specific task?A program is a set of instructions that can be executed by a computer to do a specific task. A collection of computer programs, libraries, and related data are referred to as software.
What is the term used to describe a set of instructions used to solve a problem?An algorithm is a procedure used for solving a problem or performing a computation. Algorithms act as an exact list of instructions that conduct specified actions step by step in either hardware- or software-based routines.
What is a set of instructions called?A set of instruction given to a computer is called a program.
What type of system is designed to perform one specific function?Special purpose application software is a type of software created to execute one specific task. For example a camera application on your phone will only allow you to take and share pictures. ... Other examples of special purpose application software are web browsers, calculators, media players, calendar programs etc.
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