Introduction and Constraints

Introduction

Theoretical understanding of the algorithm is essential, but it is insufficient. To solve any algorithm design problem, we’ll use the five-step strategy outlined below:

• Constraints
• Ideas Generation
• Complexities
• Coding
• Testing

Let’s discuss constraints in detail.

Constraints

Knowing the algorithms and constructing a decent computing framework isn’t enough to solve a technological problem. In technical interviews, the interviewer is interested in seeing how you solve a dilemma. Often, people make mistakes by failing to ask follow-up questions about an issue. They make a lot of assumptions at once and start dealing with them. Before you start solving a dilemma, you need to get a lot of information from the interviewer.

In this step, we write down all of the problem’s constraints. Interview questions aren’t like test questions where any aspect of a topic is well known. The interviewer wants you to ask questions to explain the issue during the interview.

Let’s look at an example to clarify what we mean by constraints.

Example

Let’s suppose that our interviewer has asked us to write an algorithm to sort numbers. We’ll get clarifications about the following:

• The first thing we need to know is what sort of data is being given. Assume that the data consists of integers.
• The size of the data is the second piece of information we need to know. The algorithm we design will be different for different input sizes. We’ll have one algorithm for 100 integers and another for 1 billion integers.

Basic guidelines for the constraints for an array of numbers

• What is the maximum number of elements in an array?
• What is the spectrum of each element’s value?
• What are the minimum and maximum values?
• What type of information is contained in each element? Is it a floating-point or an integer?
• Does the array contain unique data or not?

Basic guidelines for the constraints for an array of string

• What is the total number of elements in the array?
• How long are each of the strings? What is the shortest and longest length?
• Does the array contain any data that is unique?

Basic guidelines for the constraints for a graph

• In the graph, how many nodes are there?
• How many edges does the graph have?
• Is the graph weighted? What is the weight range?
• Does the graph have directed edges or undirected edges?
• Does the graph have a loop?
• Does the graph have a negative sum loop?
• Are there any self-loops in the graph?