Data Structures and Algorithms (DSAs)

A repository for Data Structures and Algorithms in Swift.

Table of Contents

Interview Strategy

• Clarify the problem
• Explain brute-force approach first
• Improve it step-by-step (optimize)
• Talk while coding - explain your logic
• Run through edge cases
• Analyze time and space complexity
• Be open to hints from the interviewer

1. Big O Notation

2. Algorithms and Pseudocode

3. Functions, Recursion and the Call Stack

• Higher Order Functions

4. Built-in Data Structures

• String
  • LeetCode
  • HackerRank
  • Destination City
  • Reverse String
  • Unique Email Addresses
  • First Unique Character in a String
  • Custom Sort String
• Character
• CharacterSet
• Array
  • LeetCode
  • Kids With the Greatest Number of Candies
  • How Many Numbers Are Smaller Than the Current Number
  • Max Area of Island
  • Product of Array Except Self
  • Task Scheduler
• Set
• Dictionary
  • LeetCode

5. Abstract Data Structures

• Stack
  • LeetCode
• Queue
  • LeetCode
• Linked List
  • LeetCode
  • Middle of the Linked List
  • Delete Node in a Linked List
  • Reverse Linked List
  • Convert Sorted List to Binary Search Tree
  • Linked List Cycle
• Hash Table
  • LeetCode
• Binary Tree
  • LeetCode
  • Binary Tree Inorder Traversal
  • Binary Tree Level Order Traversal
  • Maximum Depth of Binary Tree
• Binary Search Tree
  • LeetCode
  • Search in a Binary Search Tree
  • Insert into a Binary Search Tree
  • Serialize and Deserialize BST
  • Validate Binary Search Tree
  • Balanced Binary Tree
• Heap
  • LeetCode
• Trie
  • LeetCode
• Graph
  • LeetCode

6. Sorting Algorithms

• Bubble Sort
  • LeetCode - Sort Colors
• Insertion Sort
  • LeetCode - Insertion Sort List
• Quick Sort
  • LeetCode - Sort an Array
• Merge Sort
  • LeetCode - Sort an Array
  • LeetCode - Merge Sorted Array
  • LeetCode - Merge Two Sorted Lists
  • LeetCode - Merge k Sorted Lists

LeetCode - Sort Problems

7. Searching Algorithms

• Binary Search
  • LeetCode

8. Related Topics and Algorithms

• Recursion
  • LeetCode
  • HackerRank
• Dynamic Programming and Memoization
• Divide and Conquer
• Kadane
• Two Pointers
  • LeetCode
• Backtracking
• BFS
• DFS
• Sliding Window
• Bit Manipulation
  • LeetCode

9. Resources

Books

1. Cracking the Coding Interview
2. Swift Coding Challenges - by Paul Hudson
3. DSA
4. Ray Wenderlich: Data Structures and Algorithms

Video

1. HackerRank - Big O
2. HackerRank - Solving Algorithms

Time and Space Complexity

1. Big O Cheatsheet
2. Understanding Space Complexity
3. Interview Cake - Big O Notation
4. moducode - Time & Space Complexity in Functions – Big O Notation

Coding Resource Sites

1. GeeksForGeeks
2. Ray Wenderlich - Swift Algorithm Club

Other Articles

1. How to make a cake
2. Interview Cake - Call Stack
3. HWS - Measuring executing speed
4. Practice coding in a Google Doc

Must Read

1. 8 time complexities that every programmer should know
2. 8 Data Structures every programmer must know

On Interviewing

1. What's it like to interview at Pinterst

Online IDEs

1. repl.it
2. coderpad.io
3. Using STDIN for inputs and STDOUT for outputs

Sites for Coding Practice

1. LeetCode
2. HackerRank
3. Codility
4. Puzzles
5. Pramp
6. Top 10 Algorithms in Interview Questions
7. Interview Cake
8. Prepfully
9. Project Euler 10.Practice Problems Sorted by Company Interest 11.500 Data Structures and Algorithms

Mathematics

1. Brilliant.org - Discrete Mathematics

Documentation

1. Apple docs - Memory footprint of a given instance
2. Swift Algorithms