dsa2 min read
Amazon — Top K Frequent Elements (Bucket Sort / Heap)
Find the k most frequent elements using a max-heap or bucket sort. O(n) bucket sort approach using frequency as bucket index — faster than O(n log n) heap.
Read →
All Posts
1575 articles
dsa2 min read
Meta — Binary Tree Right Side View (BFS Level Order)
Return the values visible from the right side of a binary tree — the last node of each BFS level. O(n) BFS with level tracking.
Read →
dsa2 min read
Amazon — Two Sum and Variants (HashMap, Sorted, 3Sum, 4Sum)
Comprehensive coverage of Two Sum, Two Sum II (sorted), 3Sum, and 4Sum. Amazon frequently tests these variants to gauge understanding of hashmap vs two-pointer trade-offs.
Read →
dsa2 min read
Google — Word Break II (DP + Backtracking with Memoisation)
Return all ways to segment a string into dictionary words. Combines DP validity check with DFS+memo backtracking to avoid TLE on valid inputs.
Read →
dsa2 min read
Meta — Accounts Merge (Union-Find on Emails)
Merge accounts sharing common email addresses using Union-Find. Group emails by owner, merge accounts with shared emails, sort each merged group.
Read →
Page 301 of 315