zack-w

/*
  Copy List with Random Pointer - LeetCode: https://leetcode.com/problems/copy-list-with-random-pointer/
*/

// This code passes all Leetcode test cases as of Oct. 3rd 2019
class LinearSpaceApproach {
  public Node copyRandomList(Node head) {
    if (head == null) {
      return null;
    }

zack-w

/*
  Merge Two Sorted Lists - LeetCode: https://leetcode.com/problems/merge-two-sorted-lists

  Authorship: ALL credit for the iterative code in this file goes to the
  authors of the book "Elements of Programming Interviews" by Adnan Aziz,
  Amit Prakash, and Tsung-Hsien Lee.
  
  I have just adapted the solution to pass on Leetcode, added explanatory
  comments, reformatted the code, & changed variable names for understanding.

zack-w

/*
  Kth Largest Element in an Array - LeetCode: https://leetcode.com/problems/kth-largest-element-in-an-array/

  This optimal solution has the same fundamental reasoning that QuickSort uses. (the partitioning subroutine)

  Check out that QuickSort video here: https://www.youtube.com/watch?v=uXBnyYuwPe8

  This code passes all Leetcode test cases as of April 18 2019
  Runtime: 1 ms, faster than 99.86% of Java online submissions for Kth Largest Element in an Array

zack-w

/*
  Quicksort. Picking the pivot is 'pivotal' to the
  algorithm's performance ;)

  This version picks the last item in the partition space
  as the pivot everytime, there are many other ways to choose
  a pivot item.

  The video to explain this code is here: https://www.youtube.com/watch?v=uXBnyYuwPe8
*/

zack-w

/*
  Sort List - LeetCode: https://leetcode.com/problems/sort-list/
  This code passes all Leetcode test cases as of Sept. 28 2019
*/

// The split subroutine
public ListNode sortList(ListNode head) {
  /*
    Base case, an empty list or a single item list. That is a sorted list,
    hence we just return the list (it is either empty or only has 1 item)

zack-w

/*
  A min heap implementation

  Array Form: [ 5, 7, 6, 10, 15, 17, 12 ]

  Complete Binary Tree Form:
                   5
              /         \
          7               6
      /     \          /     \

zack-w

/*
  Authorship: ALL credit for the code in this file goes to the authors of the
  book "Elements of Programming Interviews" by Adnan Aziz, Amit Prakash, and
  Tsung-Hsien Lee.
  
  I have just adapted the solution to pass on Leetcode, added explanatory
  comments, reformatted the code, & changed variable names for understanding.

  Sudoku Solver - LeetCode: https://leetcode.com/problems/sudoku-solver/

zack-w

/*
  Authorship: ALL credit for the code in this file goes to the authors of the
  book "Elements of Programming Interviews" by Adnan Aziz, Amit Prakash, and
  Tsung-Hsien Lee.
  
  I have just adapted the code to pass on Leetcode, added explanatory comments,
  reformatted the code, & changed variable names for understanding.

  Generate Parentheses - LeetCode: https://leetcode.com/problems/generate-parentheses

zack-w

/*
  Serialize and Deserialize Binary Tree - LeetCode:
  https://leetcode.com/problems/serialize-and-deserialize-binary-tree/

  This code passes all Leetcode test cases as of April 26 2019
  Runtime: 12 ms, faster than 62.25% of Java online submissions for Serialize and Deserialize Binary Tree.
  Memory Usage: 39.4 MB, less than 71.37% of Java online submissions for Serialize and Deserialize Binary Tree.

  The video to explain this code is here: https://www.youtube.com/watch?v=suj1ro8TIVY
*/

zack-w

/*
  Binary Tree Level Order Traversal - LeetCode:
  https://leetcode.com/problems/binary-tree-level-order-traversal/

  This code passes all Leetcode test cases as of Feb. 3 2019
  Runtime: 1 ms, faster than 82.85% of Java online submissions for Binary Tree Level Order Traversal.
  Memory Usage: 26.5 MB, less than 64.46% of Java online submissions for Binary Tree Level Order Traversal.

  The video to explain this code is here: https://www.youtube.com/watch?v=gcR28Hc2TNQ
*/