cenkc/algorithms

LeetCode, HackerRank, Codility, CTCI - Cracking The Coding Interview & Miscellaneous algorithms and data structures studies & solutions

Algorithms (LeetCode, HackerRank, Codility, CTCI - Cracking The Coding Interview & Miscellaneous studies & solutions)

Problem Tags
Binary Search
Binary Tree
Breadth First Search (BFS) (Both BSTs and Graphs)
Depth First Search (DFS) (Both BSTs and Graphs)
Divide and Conquer
Dynamic Programming
Graph
Greedy
Interactive
Linked List
Minimum Spanning Tree - MST
Notes
Shortest Path
Sliding Window
Sorting
Tree
Trie

Common Pitfalls & Notes
Integer.MAX_VALUE and Integer.MIN_VALUE usages

LeetCode

PROBLEM DESCR.	SOLUTION	DIFFICULTY	RELATED TOPICS	ADDITIONAL INFO
LeetCode	1. Two Sum	🟢Easy	Array, Hash Table	Problem Set / Algorithms
LeetCode	3. Longest Substring Without Repeating Characters	🟠Medium	Sliding Window, Hash Table, Two Pointers, String	Problem Set / Algorithms
LeetCode	35. Search Insert Position	🟢Easy	Array, Binary Search	Problem Set / Algorithms
LeetCode	53. Maximum Subarray	🟢Easy	Array, Divide and Conquer, Dynamic Programming	Problem Set / Algorithms
LeetCode	62. Unique Paths	🟠Medium	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	64. Minimum Path Sum	🟠Medium	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	70. Climbing Stairs	🟢Easy	Math, Dynamic Programming, Memoization	Problem Set / Algorithms
LeetCode	74. Search a 2D Matrix	🟠Medium	Array, Binary Search, Matrix	Problem Set / Algorithms
LeetCode	94. Binary Tree Inorder Traversal	🟠Medium	Hash Table, Stack, Tree	Problem Set / Algorithms
LeetCode	98. Validate Binary Search Tree	🟠Medium	Tree, Depth-first Search	Problem Set / Algorithms
LeetCode	101. Symmetric Tree	🟢Easy	Tree, Depth-first Search, Breadth-first Search	Problem Set / Algorithms
LeetCode	102. Binary Tree Level Order Traversal	🟠Medium	Tree, Breadth-first Search	Problem Set / Algorithms
LeetCode	104. Maximum Depth of Binary Tree	🟢Easy	Tree, Depth-first Search	Problem Set / Algorithms
LeetCode	107. Binary Tree Level Order Traversal II	🟢Easy	Tree, Breadth-first Search	Problem Set / Algorithms
LeetCode	111. Minimum Depth of Binary Tree	🟢Easy	Tree, Depth-first Search, Breadth-first Search	Problem Set / Algorithms
LeetCode	118. Pascal's Triangle	🟢Easy	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	121. Best Time to Buy and Sell Stock	🟢Easy	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	122. Best Time to Buy and Sell Stock II	🟢Easy	Array, Greedy	Problem Set / Algorithms
LeetCode	124. Binary Tree Maximum Path Sum	🔴Hard	Dynamic Programming, Tree, Depth-first Search, Binary Tree	Problem Set / Algorithms
LeetCode	130. Surrounded Regions	🟠Medium	Depth-first Search, Breadth-first Search, Union Find	Problem Set / Algorithms
LeetCode	139. Word Break	🟠Medium	Hash Table, String, Dynamic Programming, Trie, Memoization	Problem Set / Algorithms
LeetCode	144. Binary Tree Preorder Traversal	🟠Medium	Stack, Tree	Problem Set / Algorithms
LeetCode	145. Binary Tree Postorder Traversal	🔴Hard	Stack, Tree	Problem Set / Algorithms
LeetCode	198. House Robber	🟠Medium	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	200. Number of Islands	🟠Medium	Depth-first Search, Breadth-first Search, Union Find	Problem Set / Algorithms
LeetCode	206. Reverse Linked List	🟢Easy	Linked List	Problem Set / Algorithms
LeetCode	208. Implement Trie (Prefix Tree)	🟠Medium	Hash Taable , String , Design , Trie	Problem Set / Algorithms
LeetCode	213. House Robber II	🟠Medium	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	230. Kth Smallest Element in a BST	🟠Medium	Binary Search, Tree	Problem Set / Algorithms
LeetCode	237. Delete Node in a Linked List	🟢Easy	Linked List	Problem Set / Algorithms
LeetCode	278. First Bad Version	🟢Easy	Binary Search, Interactive	Problem Set / Algorithms
LeetCode	300. Longest Increasing Subsequence	🟠Medium	Array, Binary Search, Dynamic Programming	Problem Set / Algorithms
LeetCode	501. Find Mode in Binary Search Tree	🟢Easy	Tree	Problem Set / Algorithms
LeetCode	509. Fibonacci Number	🟢Easy	Math, Dynamic Programming, Recursion, Memoization	Problem Set / Algorithms
LeetCode	518. Coin Change II	🟠Medium	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	559. Maximum Depth of N-ary Tree	🟢Easy	Depth-first Search, Breadth-first Search	Problem Set / Algorithms
LeetCode	675. Cut Off Trees for Golf Event	🔴Hard	Breadth-first Search	Problem Set / Algorithms
LeetCode	700. Search in a Binary Search Tree	🟢Easy	Tree	Problem Set / Algorithms
LeetCode	701. Insert into a Binary Search Tree	🟠Medium	Tree	Problem Set / Algorithms
LeetCode	704. Binary Search	🟢Easy	Array, Binary Search	Problem Set / Algorithms
LeetCode	746. Min Cost Climbing Stairs	🟢Easy	Array, Dynamic Programming	Problem Set / Algorithms
LeetCode	938. Range Sum of BST	🟢Easy	Tree, Recursion	Problem Set / Algorithms
LeetCode	957. Prison Cells After N Days	🟠Medium	Hash Table	Problem Set / Algorithms
LeetCode	997. Find the Town Judge	🟢Easy	Graph	Problem Set / Algorithms
LeetCode	1137. N-th Tribonacci Number	🟢Easy	Math, Dynamic Programming, Memoization	Problem Set / Algorithms
LeetCode	1143. Longest Common Subsequence	🟠Medium	String, Dynamic Programming	Problem Set / Algorithms
LeetCode	1221. Split a String in Balanced Strings	🟢Easy	String, Greedy	Problem Set / Algorithms
LeetCode	1710. Maximum Units on a Truck	🟢Easy	Greedy, Sort	Problem Set / Algorithms
LeetCode	TreasureIsland		Depth-first Search, Breadth-first Search	Interview Question / Amazon
LeetCode	TreasureIslandCenk		Depth-first Search, Breadth-first Search	Interview Question / Amazon

Codility

PROBLEM DESCR.	SOLUTION	DIFFICULTY	RELATED TOPICS	ADDITIONAL INFO
Codility	Binary Gap	🟢Easy	Iterations	Lessons / 1 - Iterations
Codility	Cyclic Rotation	🟢Easy	Arrays	Lessons / 2 - Arrays
Codility	Odd Occurrences In Array	🟢Easy	Arrays	Lessons / 2 - Arrays
Codility	Frog Jump (FrogJmp)	🟢Easy	Time Complexity	Lessons / 3 - Time Complexity
Codility	Permutation Missing Element (PermMissingElem)	🟢Easy	Time Complexity	Lessons / 3 - Time Complexity
Codility	Tape Equilibrium (TapeEquilibrium)	🟢Easy	Time Complexity	Lessons / 3 - Time Complexity
Codility	Brackets	🟢Easy	Stacks and Queues	Lessons / 7 - Stacks and Queues
Codility	Fish	🟢Easy	Stacks and Queues	Lessons / 7 - Stacks and Queues
Codility	Nesting	🟢Easy	Stacks and Queues	Lessons / 7 - Stacks and Queues

HackerRank

PROBLEM DESCR.	SOLUTION	DIFFICULTY	RELATED TOPICS	ADDITIONAL INFO
HackerRank	2D Array - DS	🟢Easy	Array	Data Structures / Arrays
HackerRank	Sales by Match	🟢Easy	Array	Algorithms / Implementation
HackerRank	Minimum Absolute Difference in an Array	🟢Easy	Greedy	Algorithms / Greedy

CTCI - Cracking The Coding Interview

PROBLEM DESCR.	SOLUTION	DIFFICULTY	RELATED TOPICS	ADDITIONAL INFO
CTCI	C1Q1 - IsUniqueChars	🟢Easy	Arrays and Strings	Data Structures / Arrays
CTCI	C1Q4 - Anagram	🟢Easy	Arrays and Strings	Data Structures / Arrays
CTCI	C1Q7 - RotateMatrix	🟢Easy	Arrays and Strings	Data Structures / Arrays
CTCI	C1Q8 - ZeroMatrix	🟢Easy	Arrays and Strings	Data Structures / Arrays
CTCI	C2Q1 - RemoveDups	🟢Easy	Linked Lists	Data Structures / LinkedLists
CTCI	C2Q2 - ReturnKthToLast	🟢Easy	Linked Lists	Data Structures / LinkedLists
CTCI	C8Q1 - TripleStep	🟢Easy	Dynamic Programming	Algorithms / Dynamic Programming

Miscellaneous

PROBLEM DESCR.	SOLUTION	DIFFICULTY	RELATED TOPICS	ADDITIONAL INFO
Misc	Longest substring length with K distinct characters	🟢Easy	Sliding Window	Algorithms / Sliding Window
Misc	Maximum Sum Of Contiguous SubArray Of Fixed Size K	🟢Easy	Sliding Window	Algorithms / Sliding Window
Misc	Smallest subarray with given sum	🟢Easy	Sliding Window	Algorithms / Sliding Window
Misc	Bubble Sort	🟢Easy	Sorting	Algorithms / Sorting
Misc	Insertion Sort	🟢Easy	Sorting	Algorithms / Sorting
Misc	Merge Sort	🟢Easy	Sorting	Algorithms / Sorting
Misc	Quick Sort	🟢Easy	Sorting	Algorithms / Sorting
Misc	Selection Sort	🟢Easy	Sorting	Algorithms / Sorting
Misc	Sorted Array	🟢Easy	Sorting	Algorithms / Sorting
Misc	Dijkstra's Algorithm	🟢Easy	Shortest Path	Algorithms / Shortest Path
Misc	Prim's Algorithm	🟢Easy	Minimum Spanning Tree - MST	Algorithms / Minimum Spanning Tree - MST
Misc	Binary Tree From Sorted Array	🟢Easy	Binary Tree	Algorithms / Study
Misc	Lru Cache Impl.	🟢Easy	Lru Cache	Algorithms / Study
Misc	Reverse LinkedList	🟢Easy	Linked List	Algorithms / Study
Misc	Biggest Two Digit Value String Fragment	🟢Easy		Algorithms / Assessments
Misc	Min Num Of Letters Must Be Deleted	🟠Medium		Algorithms / Assessments
Misc	Chain Divided Into Three Smaller Chains	🟠Medium		Algorithms / Assessments
Misc	0/1 Knapsack Problem	🟠Medium	Dynamic Programming	Problem Set / Algorithms