Robina Li

Welcome to My Technical Blog

Exploring algorithms, data structures, and software engineering insights through LeetCode solutions in Python.
NOTE: This blog is still under construction and some python code blocks may not be rendered correctly when converted from C++ with AI.

169+ Problems Solved

3 Difficulty Levels

20+ Categories

Latest Posts

Mar 22, 2026

134. Gas Station

leetcodemediumgreedyarray

Mar 21, 2026

713. Subarray Product Less Than K

leetcodemediumarraysliding-window

Mar 20, 2026

309. Best Time to Buy and Sell Stock with Cooldown

leetcodemediumdpstock

Mar 19, 2026

362. Design Hit Counter

leetcodemediumdesignqueuesliding-window

Mar 18, 2026

1448. Count Good Nodes in Binary Tree

leetcodemediumtreedfsbfs

Mar 17, 2026

1376. Time Needed to Inform All Employees

leetcodemediumtreegraphdfsbfs

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All Posts

Oct 22, 2025

LC 348: Design Tic-Tac-Toe

leetcodemediumdesignarray

Oct 22, 2025

LC 419: Battleships in a Board

leetcodemediumarraymatrix

Oct 21, 2025

LC 545: Boundary of Binary Tree

leetcodemediumtreedfs

Oct 21, 2025

LC 347: Top K Frequent Elements

leetcodemediumarrayhash-tableheap

Oct 21, 2025

LC 973: K Closest Points to Origin

leetcodemediumarraysorting

Oct 21, 2025

LC 1207: Unique Number of Occurrences

leetcodeeasyarrayhash-table

Oct 20, 2025

207. Course Schedule

leetcodemediumgraphtopological-sortcycle-detection

Oct 20, 2025

133. Clone Graph

leetcodemediumgraphdfsbfsclone

Oct 20, 2025

752. Open the Lock

leetcodemediumbfsshortest-pathlock

Oct 20, 2025

314. Binary Tree Vertical Order Traversal

leetcodemediumtreebfsvertical-order