Robina Li

LeetCode 713. Subarray Product Less Than K

Given an array of positive integers nums and an integer k, return the number of contiguous subarrays where the product...

leetcodemediumsliding-windowtwo-pointers

Mar 20, 2026

LeetCode 309. Best Time to Buy and Sell Stock with Cooldown

You are given an array prices where prices[i] is the price of a stock on day i. Find the maximum...

leetcodemediumdp

Mar 19, 2026

LeetCode 1197. Minimum Knight Moves

In an infinite chess board with coordinates from -infinity to +infinity, a knight starts at (0, 0). Return the minimum...

leetcodemediumbfs

Mar 19, 2026

LeetCode 1146. Snapshot Array

Implement a SnapshotArray that supports: SnapshotArray(int length) – initializes an array of the given length (all zeros) void set(index, val)...

leetcodemediumdesignbinary-search

Mar 18, 2026

LeetCode 362. Design Hit Counter

Design a hit counter that counts the number of hits received in the past 5 minutes (300 seconds).

leetcodemediumdesignqueue

Mar 18, 2026

LeetCode 1448. Count Good Nodes in Binary Tree

Given a binary tree, a node X is good if there is no node with a value greater than X...

leetcodemediumtreedfsbfs

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Jan 20, 2026

189. Rotate Array

leetcodemediumarray

Jan 20, 2026

Algorithm Templates: Search

Minimal, copy-paste C++ for binary search, rotated arrays, 2D search, and answer-space search. Matches Data Structures lower/upper bound style.

leetcodetemplatessearchbinary-search

Jan 20, 2026

Robina Li

Welcome to My Technical Blog

Latest Posts

LeetCode 713. Subarray Product Less Than K

LeetCode 309. Best Time to Buy and Sell Stock with Cooldown

LeetCode 1197. Minimum Knight Moves

LeetCode 1146. Snapshot Array

LeetCode 362. Design Hit Counter

LeetCode 1448. Count Good Nodes in Binary Tree

All Posts

189. Rotate Array

Algorithm Templates: Search

327. Count of Range Sum

236. Lowest Common Ancestor of a Binary Tree

211. Design Add and Search Words Data Structure

1701. Average Waiting Time

645. Set Mismatch

409. Longest Palindrome

387. First Unique Character in a String

349. Intersection of Two Arrays