This repository is updated frequently to reflect my preparation for software engineering interviews in 2020.

• Data Structures
• Algorithms
• Java Language
• Object Oriented Design
• System Design
• Full-Stack Development

Tip: Declare with interface, instantiate with implementation.
Exception: For PriorityQueue, use PriorityQueue for declaration and instantiation.

• Resizable array
• Queue and stack (Circular Array / linked list)
• HashMap (seperate chaining)
• Binary heap

• Serialize and deserialize trees (Regular / BST)

// check k-th bit
(x >> k) & 1

// Set k-th bit to 1
x = x | (1 << k)

// Set k-th bit to 0
x = x & ~(1 << k)

COMING SOON

• Find first occurrence
• Find last occurrence
• Search in shifted sorted array
• Search in bitonic array

• Median of two sorted arrays
• K closest in sorted array
• K closest in two sorted arrays

• Selection sort (array / two stacks)
• Merge sort (array / linked list)
• Quick sort

• Move 0s to the end (order not maintained / maintained)
• Dutch national flag problem

• Reverse linked list (reverse all / two at a time / k at a time)
• Middle node
• Cycle (cycle existence / cycle position)
• Reorder list
• Partition list
• List palindromicity
• Merge sorted lists (two lists / k lists)
• Linked list arithmetics (addition / subtraction)

• Queue by two stacks
• Stack by queues
• Min stack
• Deque by three stacks

• Tree properties (height / balanced / complete / symmetric / is binary search tree)
• Tree iterative traversals (preorder / inorder / postorder)
• Binary search tree basic operations (search / insert / delete)
• Build trees based on traversals
• Least Common Ancestor problems (without parent pointer / with parent pointer)
• Iterator problems

• Kth problem (Kth smallest in unsorted array, Kth closest points to origin in 3D)
• Bipartite graph

• Subsets
• Permutations (numbers / valid parentheses)
• Combinations
• Coin change
• N Queens

• Top K frequent words
• Remove Adjacent Repeated Characters
• Substring problem (Check Substring Exists)
• String Manipulation (Compression / Decompression / Abbreviation / Replacement)
• Anagram Problems
• Longest Substring Problems

• Subarray and subsequence (ascending / sum)
• Array hopper (can reach destination / minimum jumps)
• "Cutting" problem
• Edit distance
• Largest Shape Problem

• Final, finalize, finally
• Static
• Abstract class vs. interface
• Types of classes
• Overload vs. Override
• Comparable and Comparator
• Exception handling
• Concurrency

COMING SOON

COMING SOON

COMING SOON