YoungForest's blog

Late-start contest notes on trust relationships, four-direction searches, maximum binary trees and efficient grid illumination.

A practical guide to queues and stacks, covering implementations, circular queues, BFS, DFS, and building one structure from the other.

Four contest solutions cover cousin nodes, multi-source BFS for rotting oranges, greedy fixed-window flips, and square-sum permutations.

A structured guide to recursion, recurrence relations, memoization, complexity analysis, call stacks, and tail-recursion optimization.

Post-holiday contest notes on digitwise addition, union-find, reverse calculator reasoning and two-window distinct-subarray counting.

New Year's Eve catch-up and interview reflection through even-sum queries, leaf-to-root strings, interval intersections and vertical tree traversal.

Travel-day contest and phone-interview notes on alternating strings, time maps, ticket costs, bitwise triples and communicating under pressure.

A friendly contest milestone through sorted squares, turbulent runs, coin distribution in trees and a backtracking path over every grid cell.

A contest setback revisited through closest points, maximum-perimeter triangles, matched prefix remainders and ordered odd-even jumps.

Progress after switching to C++ through power sums, pancake sorting, tree flips, rational equality and renewed language fundamentals.