[Leetcode] Longest Repeating Character Replacement

[Leetcode] Design Add and Search Words Data Structure

A divergence of trie. While some solution uses Trienode, it may be too slow and a simple dictionary could work.

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[Leetcode] Top K Frequent Elements

Use partial sorting to outperform O(nlogn).

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[Leetcode] Find Minimum in Rotated Sorted Array

Use binary search to locate pivot of rotation.

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Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7]…

[Leetcode] Construct Binary Tree from Preorder and Inorder Traversal

[Leetcode] Implement Trie (Prefix Tree)

Practice template of DFS in tree. The interesting difference is the trie permits multiple decendants rather than two in same level.

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[Leetcode] Course Schedule

The condition of question leads to Cycle detection for directed graph. DFS would help.

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There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites…

[Leetcode] Non-overlapping Intervals

A good practice for the greedy algorithm. To waive duplicate computation, keep one local observatory variable and update it along the iteration.

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[Leetcode] Container With Most Water

A classic practice for two pointers.

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