Weekly coding interview problems with detailed solutions

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Project status

It is a work in progress.

The current number of questions and solutions in total is 47. It is increased by 4-6 questions every week.

I am hoping to get to several hundreds and reduce it to the top 100 critical ones. The goal is to build a solid foundation for one's next coding interview.

Table of Contents

• Interview Cake
  • Array and string manipulation
    • Merge meeting times
    • Reverse string in place
    • Reverse words
    • Merge sorted arrays
    • Single riffle shuffle
  • Hashing and hash tables
    • In-flight entertainment
    • Permutation palindrome
    • Word cloud data
    • Top scores
    • Find duplicate files
  • Greedy algorithms
    • Apple stocks
    • Highest product of three
    • Product of all other numbers
    • In-place shuffle
  • Sorting, searching, and logarithms
    • Find rotation point
    • Find repeat
  • Trees and graphs
    • Balanced binary tree
    • Binary search tree checker
    • 2nd largest item in a binary search tree
    • Graph coloring
    • MeshMessage
  • Dynamic programming and recursion
    • Recursive string permutations
    • Compute nth Fibonacci number
    • Making change
    • The cake thief
  • Queues and stacks
    • Largest stack
    • A queue with two stacks
    • Parenthesis matching
    • Bracket validator
  • Linked lists
    • Delete node
    • Linked list has a cycle
    • Reverse a linked list
    • Kth to last node
  • General programming
    • Rectangular love
    • Temperature tracker
  • Bit manipulation
    • The stolen breakfast drone
  • Combinatorics, probability, and other math
    • Which appears twice
    • Find in ordered set
    • Simulate 5-sided die
    • Simulate 7-sided die
    • Two egg problem
  • TODO: System Design
• Practical Algorithms and Data Structures
• LeetCode
  • Array/String
    • Two Sum I
    • Two Sum II
    • Valid Palindrome
    • Implement strstr()
    • Reverse words in string
  • Math
  • Linked list
  • Binary tree
  • Bit manipulation
    • Single Number I
    • Single Number II
  • Misc
  • Stack
  • Dynamic programming
  • Binary search
• Cracking the Coding Interviews
  • Bit manipulation
    • Bit operation
    • Bit insertion
• Elements of Programming Interviews
• Other
  • Data structures
    • Linked List
    • Queue
    • Stack
    • Tree
      • Balanced binary tree
      • Binary tree traversals
    • Graph
    • Trie
    • Heap
    • Priority Queue
    • Bloom filter
    • LRU cache
  • Sorting
    • Bubble sort
    • Selection sort
    • Insertion sort
    • Merge Sort
    • Quicksort
    • Heapsort
    • Counting Sort
    • Radix Sort

Testing

make test

For more information,

make help

References

• Sorting algorithm cheat sheet

Stargazers over time