Algorithm Interview Question

Introduction to Algorithms

1. What is an Algorithm?
Data structures and algorithms are core concepts in every dev interview, regardless of whether you are a C, Java, Web or Mobile developer. No matter what field of information technology you are in, you need to know about algorithms.

A programmer needs to have a thorough understanding of both data structures (arrays, linked lists, trees, stacks, queues, etc.) and algorithms like Binary Search, Dynamic Programming, etc. Therefore, this article mainly focuses on algorithms - introduction to algorithms, with 30 algorithm interview questions.

First of all, the first and most common question asked by most people is "What is an algorithm?". The complete answer can be: An algorithm is a finite set of well-defined instructions, executable by a computer, usually to solve a class of problems or to perform a computation.

Algorithms are often used to specify how computations, data processing, automated reasoning, automated decision making, and other tasks need to be performed. An algorithm is an efficient method, which can be expressed in a finite space and time, and in a well-defined formal language, to compute a function. Starting from an initial state and an initial input (input - which may be empty), when executed, it will proceed through a finite number of well-defined successive states, and finally produce an output and stop at the final state. The transition from one state to another does not have to be deterministic, some algorithms are called randomized algorithms, which incorporate random inputs.

2. Benefits of algorithms

• Increase the efficiency of an existing solution.
• Easy to use to compare the performance of different algorithms for the same problem using methods such as time complexity, space complexity, etc.
• Algorithms provide a blueprint with detailed descriptions of the core to solve the problem.
• Helps to understand the flow of the program.
• Algorithms evaluate how well the approaches perform in different scenarios (Best case, Worst case, Average case).
• An algorithm also determines what resources (input/output) are needed.
• We can quantify and evaluate the complexity of the problem in terms of time and space using algorithms.
• Design costs will be reduced if appropriate algorithms are used.