What basic data structures and algorithms should one learn before starting competitive programming?

What basic data structures and algorithms should one learn before starting competitive programming?

Introduction

Competitive programming can be considered an intellectual sport of sorts; this sport relies heavily on problem-solving processes as individuals are required to use the programming to create solutions. This process must be fueled by a profound fluency in algorithms and data structures. Use our algorithm to generate good sentences: Lack of acquaintance with key data structures and solving algorithms would be the first barrier to overcome when getting ‘hip-deep’ in competitive programming.

Table of Contents

Data Structures

Data structures are a manner of organizing and storing the data in such a way as to facilitate its rapid processing by making possible its access and manipulation in a definable form. They serve as a representation of how topics can be joined together and how operations can be executed on the data. Among the simpler and fundamental data structures, there are few data structures that every aspiring competitive programmer should be able to use competently before starting competitive programming.

Arrays

An array is a simple and generally most utilized data structure that is employed to store multiple elements of one kind. That makes understanding the creation of an array and getting and using elements and iteration over them necessary. Array serves as a building brick of stacks, queues, etc.

Stacks and Queues

Nodes are dynamic lists with elements maintained in a particular arrangement. A stack uses the Last-In-First-Out (LIFO) principle hence the last element added is the first element operated on. While the queue is arranged by the First-In-First-Out (FIFO) principle, the queue tends to follow upon another. Knowing these data structures is an important skill because they are, in fact, usually pointed to in numerous algorithms.

Linked Lists

A linked list is a linear data structure every node of which has a pointer that points to the next element. It is a very flexible data structure because it permits operations of insertions and deletions may take place efficiently. Such is the essence of a linked list which is the basis for many data structures like stack, queue, etc.

Trees

Trees are Hierarchical data structures with different elements or nodes that are connected hierarchically without any cycles in them. The use of these algorithms has been in many fields of computer science, for instance, operating systems, graphics, databases, and network computers. Tree traverse and manipulation on the trees is a crucial item to get aquire of knowledge.

Algorithms

Algorithms are usually instructions written codes that enable computers to perform specific tasks satisfactorily. They are irreplaceable for coding in complex problems where one has to prepare a working presentation for the race of participants. The following are the key algorithmic knowledge you need to know about.

Sorting Algorithms

In different use cases, sorting can be the most common process. The algorithms of sorting are plenty, each one of them having its significant advantages and disadvantages. These encompass Bubble Sort, Selection Sort, Insertion Sort, Quicksort, and Mortoneach which have their unique strengths and weaknesses.

Searching Algorithms

The searching algorithm is the process of locating a certain item from a collection among all the other items. It may be done on separate or external data structures too. Linear Search and Binary Search are among the algorithms of searching that every computer programmer learns and employs throughout his career.

Graph Algorithms

Graphs are an important ingredient of mathematics that depict binary relationships between entities. Graph algorithms are an unparalleled category of algorithms and as such, they offer an effective solution to numerous problems of competitive programming. The algorithms involved in this course are DFS (Depth-First Search), BFS (Breadth-First Search), and procedures for shortest path which include Dijkstra’s and Floyd–Warsh all’s

Hashing

Hashing is the mechanism to pinpoint a specific object out there in a system from a group of similar objects. In the case when the algorithms demand a constant time function, hashing can be a nice tool to provide the solution. Hashing associates only distinct items with distinct keys, these being generated by hash functions. The keys to accessing these data are the hash codes. The hash technique is widely used in algorithms and data structures like symbol tables, database indexing, and caches, just to name a few examples.

Dynamic Programming

Dynamic Programming (DP) is a problem-solving paradigm that utilizes an algorithmic approach to breaking a given complex problem into its subproblems. Once the results of its subproblems have been computed then these results are stored and consequently reused to prevent unnecessary computations. As it is proved, many problems in competitive programming use DP due to its fastness. The programmer most commonly uses graph search techniques for the optimization problems which can be of the shortest path finding in a graph or the longest increasing subsequence in an array.

Greedy Algorithms

Greedy algorithms work on a step-by-step basis with local optimum objectives at each stage, keeping in mind the hope of arriving at the global optimum. This algorithm keeps in mind its best choice at every step, all the time being on its way to finding out the best solution. The ‘greedy’ approach helps to solve many problems, for example, Knapsack, minimum spanning tree, and Dijkstra’s algorithm for path shortening are the most well-known.

Divide and Conquer

The approach that is known as Divide and Conquer is the algorithmic paradigm where all branches are solving the problem and the solutions are combined recursively. The divide and conquer algorithm breaks down a problem into two or more sub-problems which may be of the same type or related, and may be recursively solved until this becomes a simple enough one to be solved directly. Unlike the sub-problems’ solutions which are subsequently used to arrive at the original problem’s solution. This method requires the formulation of the recursion relation and the resolution of the boundary conditions, every day we use this technique to create efficient algorithms for various problems as like, sorting (e.g., quicksort, mergesort), multiplying large numbers (e.g., Karatsuba algorithm), syntactic analysis (e.g., top-down parsers), and computing the discrete Fourier transform (FFT).

Recursion

Recursion is the approach to rewrite the solutions of certain problem instances by usually considering smaller instances of the same problem. Recursion understanding is a challenging task because it is very popular in data structure-related and algorithmic problems. This is indeed a crucial issue in both competitive programming and some of the other data structures and algorithms, required to handle tough problems.

Backtracking

The Bakrack argument technique is an algorithm used for finding feasible solutions through the bottom approach, which maintains to start constructing the solution from the bottom, one piece at a time, and it discards satisfactory ones at any point in time. It is a type of math that addresses a problem if you need to select the best method that is required to complete something or if you need to find all possible methods. The examples of problems in which a backtracking approach can be used are light problems like the Eight Queens problem, producing all the subsets of a set and finding all the permutations of a string.

Bit Manipulation

Bitwise operations are utilized in competitive coding with much essence. The data structure used here is a number line with some unknown positive number and the code is both simpler and faster. The operation called the bit manipulation is set to solve problems that are represented in the binary form. In most cases, this operation allows the solution to the problem to be more effective. Bit manipulation is not a usual aid, but it might add a cool extra point in competitions.

Time and Space Complexity Analysis

Knowing how to conduct time and space complexity analysis is an essential factor in having an edge in competitive programming. This task consists of measuring various parameters including execution time and memory space data taken up after the algorithm is done with processing. Very often you can choose which algorithm will be the most optimal for solving a particular problem so that you can take advantage of time and space. If so, do not worry. This is especially critical when speaking of competitive programming as efficiency is one of its main concerns.

Conclusion

Let us consider the data structure and algorithm concepts of data structure and sorting algorithms, which further form the basis of competitive programming. It helps you to get a grasp of more complicated data structures and algorithms as well as polishes your problem-solving abilities so that they are more complex ones. Recall that the main factor of how you will become a competitive programmer is practicing the algorithms. Therefore, keep writing code, and keep adjusting the result.