Exploring Basic Data Structures and Their Applications in LeetCode Problems
Data structures are the foundation of computer science, providing efficient ways to manage and organize data. This blog post delves into three fundamental data structures: Arrays, Linked Lists, and Stacks. We'll explore their characteristics, operations, and how they are used to solve various LeetCode problems.
1. Arrays
Introduction to Arrays
An array is a collection of elements identified by an index or key. Arrays store elements in contiguous memory locations, allowing constant-time access to elements by their index. They are one of the simplest and most widely used data structures.
Characteristics:
Fixed-size: The size of the array is determined at the time of creation and cannot be changed.
Indexed: Elements are accessed by their position or index, starting from 0.
Homogeneous: Typically, arrays store elements of the same data type.
Basic Operations:
Accessing Elements: Constant time access to any element using its index.
Insertion and Deletion: Inserting or deleting elements can be expensive as shifting elements may be required.
Application: Group Anagrams
Leetcode Problem Group Anagrams
Given an array of strings, group anagrams together. An anagram is a word formed by rearranging the letters of another word.
Link to Solution
We use an array to store the grouped anagrams. The approach involves sorting each string and using the sorted string as a key in a hash map.
2. Linked Lists
Introduction to Linked Lists
A linked list is a linear data structure where elements are stored in nodes, and each node points to the next node, forming a sequence. Unlike arrays, linked lists do not store elements in contiguous memory locations.
Characteristics:
Dynamic size: Linked lists can grow or shrink in size by allocating or deallocating memory.
Pointers: Each node contains a reference (or pointer) to the next node in the sequence.
No random access: Accessing elements requires traversing the list from the beginning.
Basic Operations:
Traversal: Moving from one node to the next.
Insertion: Adding a node at the beginning, end, or middle.
Deletion: Removing a node from the list.
Application: Leetcode problem reverse linked list
LeetCode Problem: Reverse Linked List
Given a linked list reverse the linked list
Link to Solution
3. Stacks
Introduction to Stacks
A stack is a linear data structure that follows the Last In, First Out (LIFO) principle. It allows operations at one end, typically the top of the stack.
Characteristics:
LIFO: The last element added is the first to be removed.
Operations: Two primary operations are
push(add an element) andpop(remove the top element).
Basic Operations:
Push: Add an element to the top of the stack.
Pop: Remove the top element from the stack.
Peek: View the top element without removing it.
Application: Minimum Window Substring
Leetcode Problem Minimum Window Substring:
Given two strings s and t, find the minimum window in s which will contain all the characters in t.
Link to Solution
We use a stack to keep track of the characters in the current window and their positions.
Ending Remarks:
Understanding and effectively using basic data structures such as Arrays, Linked Lists, and Stacks is crucial for solving a wide range of problems in computer science and programming. By exploring these structures and applying them to solve LeetCode problems, we gain insights into their practical applications and benefits.
Arrays provide efficient access and are suitable for problems like grouping anagrams. Linked lists offer dynamic size and efficient insertions, making them ideal for interval insertion problems. Stacks follow the LIFO principle, helping in scenarios like finding the minimum window substring.
Thank you for reading...