YoungForest's blog

Four solutions build a recurrence array, enforce unique frequencies, sell diminishing ball stacks by layer, and count sorted insertion cost.

Contest solutions concatenate distinct pieces, count sorted vowel strings, reserve ladders for the largest climbs, and select a path with combinations.

A biweekly review of frequency sorting, the widest empty vertical strip, brute-force substring pairs differing once, and memoized column-frequency DP.

Four solutions track key duration, test arithmetic subarrays, minimize path effort, and transform matrix ranks by connectivity.

A contest recap on endpoint spans, cyclic string operations, conflict-free teams, and thresholded graph connectivity.

A biweekly review covers trimmed means, network-quality search and segment DP; problem three passed two minutes late and problem four stayed unimplemented.

Four solutions cover nesting depth, city network rank, cross-string palindromes, and connected subtrees grouped by diameter.

Contest solutions cover a special array, parity tree, circular viewing window and recursive bit operations; the last was learned after the contest.

A biweekly review covers parking capacity, access alerts, row-column matrices and server rotation; only the first two were solved during the contest.

After a three-month pause, this review covers folder levels, direct simulation, preorder traversal and subset enumeration amid internship and recruiting.