Coding Interview
252. Meeting Rooms
Jason Yang · 04 Aug, 2026
Meeting Rooms (LeetCode 252): sort intervals by start, then one pass reveals whether any two overlap. Java code, the strict-vs-equal trap, and complexity.
Blog posts — page 5
Coding Interview
242. Valid Anagram
Jason Yang · 04 Aug, 2026
Valid Anagram (LeetCode 242): why a 26-slot frequency count beats sorting, the one-array Java solution, and how the Unicode follow-up changes the answer.
Coding Interview
235. Lowest Common Ancestor of a Binary Search Tree
Jason Yang · 04 Aug, 2026
Lowest Common Ancestor of a BST (LeetCode 235): use the sorted-order property to walk down until the two targets split, an O(h) one-pass solution in Java.
Coding Interview
230. Kth Smallest Element in a BST
Jason Yang · 04 Aug, 2026
Kth Smallest Element in a BST (LeetCode 230): why an inorder walk visits values in sorted order, so the kth node you touch is the answer — solved in Java.
Coding Interview
226. Invert Binary Tree
Jason Yang · 04 Aug, 2026
Invert Binary Tree (LeetCode 226): swap every node's children with a three-line recursion, plus the iterative BFS version and the null base case that matters.