data structure

Count Decoding Ways for Encoded Messages

Problem Statement (Asked By Facebook) Given the mapping a = 1, b = 2, ..., z = 26, and an…

2 months ago

Implement an XOR Linked List

An XOR-linked list is a memory-efficient version of a doubly linked list. Instead of each node storing separate next and…

2 months ago

Construct and Deconstruct a Pair

Problem Statement (Asked By Jane Street) The function cons(a, b) creates a pair of two elements. Implement two functions: car(pair):…

2 months ago

Find the Smallest Missing Positive Integer

Problem Statement (Asked By Stripe) You are given an array of integers. Your task is to find the smallest missing…

2 months ago

Serialize and Deserialize a Binary Tree

Given the root of a binary tree, create two functions: serialize(root) - Converts the binary tree into a string representation.…

2 months ago

Product of Array Except Self

Problem Statement (Asked By Uber) Given a list of integers, return a new list such that each element at index…

2 months ago

Two Sum: Check for Two Numbers with Sum K

Problem Statement (Asked By Google) Given a list of integers and a target number k, determine if there exist two…

2 months ago

DSA: Heap

A heap is a specialized tree-based data structure that satisfies the heap property. It is commonly used to implement priority…

2 years ago

DSA: Trie

What is a Trie in DSA? A trie, often known as a prefix tree, is a tree-like data structure used…

2 years ago

Trees: Lowest Common Ancestor

What is the Lowest Common Ancestor? In a tree, the lowest common ancestor (LCA) of two nodes, n1 and n2,…

2 years ago