Coding Problems

Some coding problems in Java.

Problems

Array

• Compress Letters
• Shrink Space

Binary Tree

• Maximum Path Sum (?)
• Longest Increasing Path

Divide and Conquer

• Quick Sort (No duplicates)
• Merge Sort

Dynamic Programming

• Longest Palindrome (+)

Hash Map

• Valid Anagram (+)

Linked List

• Linked List Palindrome (+)
• Reverse Linked List (+)

Trie

• Search Word in 2D array (+)

+: Done; passed tests
?: Done, correctness unknown

Models

• Binary Tree Node
• Linked List Node
• A-Z Trie Node (Use array of 26. Supports character a-zA-Z)
• Map Trie Node (Use hash map. Generics)
• Array Interval Map (1,3,5,7; 1=>1, 2=>1, 3=>3, 4=>3, 7=>7, 8=>7, 9=>7)

Utilities

Binary Tree

• In-order/Pre-order traversal
• Create tree from list (leetcode's rep. Layer by layer.)

Linked List

• Java list to LinkedListNode
• Linked list to string (1->2->3->(NULL))
• Lists equality
• Count nodes
• Seek to position

Trie

• Seek child by prefix (List or String)
• Add contents (List or String)
• Build A-Z trie from collection of Strings