Concepts5

Problem Classification Patterns

Many competitive programming problems map to a small set of classic patterns; recognizing keywords and constraints lets you pick the right tool fast.

#problem classification#binary search on answer#two pointers+12

⚙️AlgorithmIntermediate

LCA - Binary Lifting

Binary lifting precomputes 2^k ancestors for every node so we can jump upward in powers of two.

#lca#binary lifting#tree+12

⚙️AlgorithmIntermediate

Bridge Tree

A bridge tree is built by contracting every 2-edge-connected component of an undirected graph into a single node, leaving only bridges as edges between nodes.

#bridge tree#2-edge-connected components#bridges+12

⚙️AlgorithmIntermediate

Tree Distances and Diameter

Tree diameter is the longest simple path in a tree and can be found with two BFS/DFS runs.

#tree diameter#tree center#eccentricity+12

🗂️Data StructureIntermediate

Sparse Table

A Sparse Table is a static range-query data structure that preprocesses an array in O(n \log n) time and answers many queries in O(1) time.

#sparse table#range minimum query#rmq+12