company prep
Problems frequently reported at LinkedIn, in course order. Solve the must-dos first.
6 easy22 medium5 hardTree DFS (bottom-up) ×5Tree BFS (level order) ×4BST property ×3Divide and conquer ×2Binary search (exact & bounds) ×2Group by a canonical key ×2
08 · Recursion
- #50Pow(x, n)Mediummust-do
09 · Math & Number Theory
- #528Random Pick with WeightMediummust-do
- #149Max Points on a LineHard
10 · Arrays & Strings
- #53Maximum SubarrayMediummust-do
13 · Sliding Window
- #76Minimum Window SubstringHardmust-do
- #1004Max Consecutive Ones IIIMediummust-do
14 · Hashing & Prefix Sums
- #205Isomorphic StringsEasy
16 · Stacks & Monotonic Stack
- #20Valid ParenthesesEasymust-do
- #150Evaluate Reverse Polish NotationMediummust-do
18 · Binary Search
- #34Find First and Last Position of Element in Sorted ArrayMediummust-do
20 · String Parsing & Expression Evaluation
- #68Text JustificationHard
21 · Tree Traversals
- #102Binary Tree Level Order TraversalMediummust-do
- #103Binary Tree Zigzag Level Order TraversalMedium
- #297Serialize and Deserialize Binary TreeHardmust-do
22 · Tree Recursion
- #104Maximum Depth of Binary TreeEasymust-do
- #100Same TreeEasy
- #226Invert Binary TreeEasymust-do
- #101Symmetric TreeEasymust-do
- #236Lowest Common Ancestor of a Binary TreeMediummust-do
23 · Binary Search Trees
- #701Insert into a Binary Search TreeMedium
- #235Lowest Common Ancestor of a Binary Search TreeMediummust-do
- #173Binary Search Tree IteratorMediummust-do
24 · Heaps & Priority Queues
- #973K Closest Points to OriginMediummust-do
- #373Find K Pairs with Smallest SumsMedium
26 · Graphs: BFS & DFS
- #1197Minimum Knight MovesMedium
- #127Word LadderHardmust-do
28 · Union-Find & Minimum Spanning Trees
- #323Number of Connected Components in an Undirected GraphMedium
- #261Graph Valid TreeMediummust-do
31 · Backtracking
- #46PermutationsMediummust-do
- #17Letter Combinations of a Phone NumberMedium
33 · Intervals
- #57Insert IntervalMediummust-do
35 · Dynamic Programming
- #152Maximum Product SubarrayMediummust-do
37 · Design Data Structures
- #380Insert Delete GetRandom O(1)Mediummust-do