Identifying the Youngest Generation in a Family Tree
Given a family tree, the task is to output the smallest generation (youngest descendants) and list all members belonging to that generation.
Input Format:
The first line contains an integer N (1 ≤ N ≤ 100,000), the total number of family members, each assigned a unique ID from 1 to N. The second line provides N integers where the i-th integer r ...
Posted on Fri, 19 Jun 2026 17:57:12 +0000 by dm3
Minimizing Camera Placement on a Binary Tree Using Greedy DFS
Given a binary tree, we need to install cameras on its nodes. Each camera can monitor its parent, itself, and its immediate children. The goal is to determine the minimum number of cameras reuqired to cover the entire tree.
Problem Constraints
Number of nodes ranges from 1 to 1000.
Node values are irrelevant (typically 0).
Core Strategy
The o ...
Posted on Fri, 05 Jun 2026 17:26:40 +0000 by buroy
Reconstructing Binary Trees Using Dual Traversal Sequences
Core Traversal DefinitionsPre-order: Process the root node, traverse the left subtree, then traverse the right subtree.In-order: Traverse the left subtree, process the root node, then traverse the right subtree.Post-order: Traverse the left subtree, traverse the right subtree, then process the root node.Building from Pre-order and In-order Sequ ...
Posted on Sat, 30 May 2026 19:04:00 +0000 by php-coder
Core Data Structure Interview Questions and Algorithmic Solutions
Stack and Queue Fundamentals
Stacks and queues share the trait that insertion and deletion occur solely at their endpoints.
Typical stack storage models are sequential arrays and linked lists.
A stack exhibits last-in-first-out behavior.
Linked lists lack random access; elemants must be traversed sequentially.
Linked representation simplifies ...
Posted on Wed, 20 May 2026 05:56:52 +0000 by Adam W
Transforming a Binary Search Tree into a Greater Sum Tree
Recall the properties of a BST:
The left subtree of a node contains only nodes with keys less than the node's key.
The right subtree of a node contains only nodes with keys greater than the node's key.
Both the left and right subtrees must also be binary search trees.
Example Scenarios
Input: [4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]
...
Posted on Mon, 11 May 2026 11:06:25 +0000 by DBHostS
Binary Tree Traversal Techniques and Common Algorithmic Patterns
Binary trees serve as foundational structures for many advanced topics such as dynamic programming and backtracking. Mastery of their traversal methods is essential.
Core Traversal Strategies
Two primary strategies exist: depth-first and breadth-first.
Depth-First Traversal
Explores as far as possible along each branch before backtracking. Vari ...
Posted on Fri, 08 May 2026 01:12:02 +0000 by mattbarber