Coding Interview

• Learning Resources
• Basics
• Complexity
• Data Structures
• Solution Patterns
• Problem Patterns
• Problems In Real Interviews

Learning Resources

• LeetCode
• HackerRank
• Algo Monster
• InterviewBit

Basics

• Java Coding
• Problems And Solutions Quick Table

Complexity

• Time Complexity
• Space Complexity

Data Structures

• String
• Array
• 2D Array
• Linked List
• Queue
• Stack
• Binary Tree
• Heap
• Trie

Solution Patterns

• Frequency Counters
• 2 Pointers
• Prefix Sum Array
• Quickselect
• Reservoir Sampling
• Heap (Priority Queue)
• Trie
• Backtraking
• Depth-First Search (DFS)
• Union Find
• Binary Search
• Sliding Window
• Divide and Conquer
• Dynamic Programming
• Greedy
• Recursion

Problem Patterns

• Top K and Kth
  • Top K
    • Get Top K Frequent Elements from Array
    • Get Top K Frequent Words from Array
    • Get Top K Closest Points to Origin
  • Kth
    • LeetCode-215 Kth Largest Element in an Array
    • LeetCode-703 Kth Largest Element in a Stream
    • LeetCode-230 Kth Smallest Element in a BST
    • LeetCode-378 Kth Smallest Element in a Sorted Matrix
• Manipulation
  • Remove
    • Remove duplicates
      • LeetCode-26 Remove Duplicates from Sorted Array
      • Remove Duplicates from List
      • Remove Duplicates from Sorted List
    • Remove by value
      • LeetCode-27 Remove Element
  • Reverse
    • Reverse List
    • Reverse Sub-list
  • Rotate
    • Rotate List Right
    • LeetCode-189 Rotate Array
    • LeetCode-796 Rotate String
  • Merge
    • LeetCode-21 Merge 2 sorted lists
    • LeetCode-23 Merge K sorted lists
    • Merge 2 Sorted Arrays
• Symmetry
  • Parentheses
    • Is Valid Parentheses
    • Generate All Combinations of Parentheses
    • Remove Minimum Parentheses to Make Parentheses Valid
    • Get All Possible Strings by Removing Minimum Number of Invalid Parentheses
  • Palindrome
    • Is Palindrome String
    • Is Palindrome String by Removing One Char
    • Is Palindrome String by Only Considering Alphanumeric Characters
    • Can Characters of String Form Palindrome
    • Is Palindrome List
• Random
  • Candidate with same weight
    • Generate Random Index of Target Number
    • Get Random Node from List
  • Candidate with different weights
    • Generate Random Index with Weight
• Frequency
  • Get Top K Frequent Elements from Array
  • Get Top K Frequent Words from Array
• Interval
  • Merge Intervals
  • Intersect 2 Interval Lists
  • Merge K Interval Lists And Find Gaps
  • LeetCode-252 Meeting Rooms
  • LeetCode-253 Meeting Rooms II
• Longest X sequence/substring
  • LeetCode-1143 Longest Common Subsequence
  • LeetCode-300 Longest Increasing Subsequence
  • LeetCode-5 Longest Palindromic Substring
  • LeetCode-298 Binary Tree Longest Consecutive Sequence
  • LeetCode-14 Longest Common Prefix
• String Prefix
  • Implement Trie
  • Implement Trie with Wildcard Seach
• Integer Calculation (Integers represents in other data structures and then calculation)
  • In String
    • LeetCode-415 Add Strings
    • LeetCode-43 Multiply Strings
    • LeetCode-67 Add Binary
  • In Array
    • LeetCode-66 Plus One
    • LeetCode-989 Add to Array-Form of Integer
  • In Linked List
    • LeetCode-2 Add Two Numbers
• Enumeration (Find all possible solutions)
  • Generate All Combinations of Parentheses
  • Get All Possible Strings by Removing Minimum Number of Invalid Parentheses
  • Get All Word Combinations for Constructing String
• Grouping
  • Get Number of Groups in Undirected Graph
  • Accounts Merge
  • Group Shifted Strings
• Detect Cycle
  • Detect Cycle in Undirected Graph
  • LeetCode-1041 Robot Bounded In Circle
• Math
  • Implement Pow(x,n)
  • Divide Two Integers

Problems In Real Interviews

Problem	Company	Interview Stage
Get Equilibrium Index from Array	Facebook	Screening
Get Sums of All Root-to-leaf Paths	Facebook	Onsite
Find Missing Ranges from Array	Facebook	Onsite
Get Range Sum of Binary Search Tree	Facebook	Onsite
Divide Two Integers	Facebook	Onsite
Optimizing Box Weights	Amazon	Screening
Gifting Group (Get Number of Groups in Undirected Graph)	Amazon	Screening