Design

• Calculator, reference implementation
  • infix to posfix, stack
• MinStack, reference implemntation

Dynamic Programming

• Longest palindrom substring , my solution

• Palindrome substrings , my solution

• UniqueBinarySearchTree , my solution

• Kth smallest in lexicographical order, my solution

• Coin Change2, my solution

• Super Washing Machines, my solution

• K Inverse Pairs Array , solution

• Find the Derangement of An Array, solution

• Decode Ways II, solution

• Maximum length of pair chain, solution

• Maximum Sum of 3 Non-Overlapping Subarrays, solution

• Delete and earn, solution

• House Robber, solution

• Student Attendance Records II , solution

• 4 Keys Keyboard , solution

• Maximum vacation days , solution

difficult recurrence equations

• Remove Boxes, solution
• Burst Balloons, solution

Recursive

• Output contest matches, my solution
• Shopping Offers, solution
• Partition to K Equal Sum Subsets, solution
• Increasing subsequences, solution

Array

• Maximum Swap, solution

Coding

• RotateImage, my solution

• Longest Repeating Character replacement , my solution

• Largest Palindrome Product, my solution and explanation

• Contiguous Array, my solution

• Minimum time differencemy solution

• Oversized Pancake Flipper from codejam2017 my review

• Tidy Numbers my review

• Bathroom stalls my review

• Minimum window substring, my solution

• Find Duplicate File In System, my solution

• Zigzag conversion, my solution

• Task Scheduler, my solution

• Minimum Factorization, my solution

• Course Schedule III, solution

• Maximum Product of Three Numbers, solution

• Design Log Storage System, solution

• Sum of Square Numbers, solution

• Solve the Equation, solution

• Encode and Decode Strings, solution

• Split Array into consecutive subsequences , solution

• My Calendar II, solution

• Parse Lisp Expression, solution

• Remove K Digits, solution

• Next Greater Element II , solution

• Construct the Rectangle , solution

• Patch Array , solution

• Game of life , solution

• Add Bold Tag in string , solution

• Sentence Screen fitting , solution

• Construct Array , solution

• CandyCrush , solution

Array

• Shortest word distance , my solution

• Shortest word distance II, my solution

• Shortest word distance III, my solution

• Maximum distance in arrays, my solution

• Rotate Array, my solution

• Zero Flip, solution

• Contiguous subarray sum, solution

• Elimination Game, solution

• Elimination Game, solution

Sliding Window

• Subarray product less than K, solution
• Anagram of substring, solution

String

• Next Cloest time, solution

bit operation

• Bitwise AND of Numbers Range, solution

Hash

• Set Mismatch, solution
• subarray sum equals to K, solution

Stack

• Longest valid parentheses, my solution

• Tag Validator, my soluion

• 312Pattern, solution

• Exclusive Time of Functions, solution

• Largestest renctangle in histogram, solution

• Maximal Rectangle, solution

• Decompress String, solution

• Basic Calculator II, solution

• Find permutation, solution

Sort

• Relative ranks,my solution

Union-find

• Redundant Connection, solution - detect cycle in tree

Tree

• Populating Next Right pointers in each node, my solution

• Nested List Weight sum, my solution

• Nested List Weight sum II , my solution

• Average of Levels in Binary Tree, solution

• K Empty slots, solution

• Range Module, solution

  • very tricky

• Merkel Hash, very genius algorith esecially for large tree

• Longest Univalue Path, solution

• Find Duplicate Subtrees, solution

segment tree

• Falling Squares, solution

Trie

• Design Search Autocomplete System, solution
• Replace Words, solution

derived

• Magic Dictionary, solution

BIT(Binary Indexed Tree)

• Range sum query, solution

Heap(PriorityQueue)

• Java default is minheap-ascending order. heap is 0-based.

• Top K frequent words, solution

• Smallest Range, solution

BST

• Reverse Pairs, my solution
• Single element in a sorted array, my solution
• Count of smaller numbers after self, my solution

Graph

• Mine Sweeper, my solution
• 01 Matrix, my solution
• Minimum Genetic Mutation, my solution
• Accounts Merge, solution
• Sentence Similarity II, solution
• Network Delay time, solution

Binary Search

• Search For a range, my solution
• Find Kth smallest pair distance, solution
• Find Missing Number, solution

Convex hull

• Erect the Fence, solution
• Convex polygon, solution

Rolling hash(Rabin Karp algorithm)

• Repeated String match , solution