Solve tree, graph, sliding-window problems
Overview
This set of problems evaluates proficiency in core data structures and algorithms, specifically binary tree traversals (including zigzag/level-order patterns), directed graph cycle detection and topological ordering, and sliding-window techniques for substring analysis.
Question
LeetCode 103. Binary Tree Zigzag Level Order Traversal – given a binary tree root, return its zigzag level-order traversal.
LeetCode 207. Course Schedule – given course prerequisites, determine if all courses can be finished by detecting cycles with topological sort.
LeetCode 340. Longest Substring with At Most K Distinct Characters – given string s and integer k, return the length of the longest substring containing at most k distinct characters.
https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/description/ https://leetcode.com/problems/course-schedule/description/ https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/description/