old a2z sheet

01Learn the basics

1.1Things to Know in C++/Java/Python or any language

• User Input / OutputIntroduction to DSA
• Data TypesIntroduction to DSA
• If Else statementsIntroduction to DSA
• Switch StatementIntroduction to DSA
• What are arrays, strings?Introduction to DSA
• For loopsIntroduction to DSA
• While loopsIntroduction to DSA
• Functions (Pass by Reference and Value)Introduction to DSA
• Time Complexity [Learn Basics, and then analyse in next Steps]Introduction to DSA

1.2Build-up Logical Thinking

• PatternsMaths, Data Structures

1.3Learn STL/Java-Collections or similar thing in your language

• C++ STLC++, Introduction to DSA
• Java CollectionsJava, Introduction to DSA

1.4Know Basic Maths

• Count DigitsMaths, Data Structures
• Reverse a NumberMaths, Data Structures
• Check PalindromeMaths, Data Structures
• GCD Or HCFMaths, Data Structures
• Armstrong NumbersMaths, Data Structures
• Print all DivisorsMaths, Data Structures
• Check for PrimeMaths, Data Structures

1.5Learn Basic Recursion

• Understand recursion by print something N timesRecursion, Data Structures
• Print name N times using recursionRecursion, Data Structures
• Print 1 to N using recursionRecursion, Data Structures
• Print N to 1 using recursionRecursion, Data Structures
• Sum of first N numbersMaths, Data Structures
• Factorial of N numbersMaths, Data Structures
• Reverse an arrayArrays, Data Structures
• Check if a string is palindrome or notString, Data Structures
• Fibonacci NumberMaths, Data Structures

1.6Learn Basic Hashing

• Hashing TheoryHashing, Data Structures
• Counting frequencies of array elementsArrays, Hashing, Sorting, Data Structures
• Find the highest/lowest frequency elementArrays, Hashing, Data Structures

02Learn Important Sorting Techniques

2.1Sorting-I

• Selection SortSorting, Arrays, Data Structures
• Bubble SortSorting, Arrays, Data Structures
• Insertion SortSorting, Data Structures

2.2Sorting-II

• Merge SortArrays, Sorting, Data Structures
• Recursive Bubble SortSorting, Data Structures
• Recursive Insertion SortRecursion, Sorting, Data Structures
• Quick SortArrays, Sorting, Data Structures

03Solve Problems on Arrays [Easy -> Medium -> Hard]

3.1Easy

• Largest Element in an ArrayArrays, Data Structures
• Second Largest Element in an Array without sortingArrays, Data Structures
• Check if the array is sortedArrays, Data Structures
• Remove duplicates from Sorted arrayArrays, Data Structures
• Left Rotate an array by one placeArrays, Data Structures
• Left rotate an array by D placesArrays, Data Structures
• Move Zeros to endArrays, Data Structures, Two Pointer
• Linear SearchArrays, Data Structures
• Find the UnionArrays, Hashing, Sorting, Data Structures
• Find missing number in an arrayArrays, Data Structures, Binary Search, Hashing
• Maximum Consecutive OnesArrays, Data Structures
• Find the number that appears once, and other numbers twice.Arrays, Hashing, Data Structures
• Longest subarray with given sum K(positives)Arrays, Data Structures, Hashing
• Longest subarray with sum K (Positives + Negatives)Arrays, Data Structures, Hashing

3.2Medium

• 2Sum ProblemArrays, Sorting, Data Structures, Two Pointer
• Sort an array of 0's 1's and 2'sArrays, Two Pointer, Data Structures
• Majority Element (>n/2 times)Arrays, Hashing, Data Structures
• Kadane's Algorithm, maximum subarray sumArrays, Data Structures
• Print subarray with maximum subarray sum (extended version of above problem)Arrays, Hashing, Data Structures
• Stock Buy and SellArrays, Data Structures
• Rearrange the array in alternating positive and negative itemsArrays, Data Structures
• Next PermutationArrays, Data Structures, Two Pointer
• Leaders in an Array problemArrays, Data Structures
• Longest Consecutive Sequence in an ArrayArrays, Hashing, Data Structures
• Set Matrix ZerosArrays, Data Structures
• Rotate Matrix by 90 degreesArrays, Data Structures
• Print the matrix in spiral mannerArrays, Data Structures
• Count subarrays with given sumArrays, Hashing, Data Structures

3.3Hard

• Pascal's TriangleArrays, Data Structures, Maths
• Majority Element (n/3 times)Arrays, Hashing, Data Structures
• 3-Sum ProblemArrays, Sorting, Two Pointer, Data Structures, Hashing
• 4-Sum ProblemArrays, Sorting, Data Structures, Two Pointer, Hashing
• Largest Subarray with 0 SumArrays, Hashing, Data Structures
• Count number of subarrays with given xor KArrays, Hashing, Data Structures
• Merge Overlapping SubintervalsArrays, Data Structures, Sorting
• Merge two sorted arrays without extra spaceArrays, Sorting, Data Structures
• Find the repeating and missing numberArrays, Maths, Hashing, Data Structures
• Count InversionsSorting, Arrays, Data Structures
• Reverse PairsArrays, Sorting, Data Structures
• Maximum Product SubarrayArrays, Data Structures

04Binary Search [1D, 2D Arrays, Search Space]

4.1BS on 1D Arrays

• Binary Search to find X in sorted arrayArrays, Binary Search, Data Structures
• Implement Lower BoundBinary Search, Arrays, Data Structures
• Implement Upper BoundArrays, Binary Search, Data Structures
• Search Insert PositionArrays, Binary Search, Data Structures
• Floor/Ceil in Sorted ArrayArrays, Data Structures
• Find the first or last occurrence of a given number in a sorted arrayBinary Search, Arrays, Data Structures
• Count occurrences of a number in a sorted array with duplicatesHashing, Arrays, Data Structures
• Search in Rotated Sorted Array IArrays, Binary Search
• Search in Rotated Sorted Array IIArrays, Binary Search
• Find minimum in Rotated Sorted ArrayArrays, Data Structures
• Find out how many times has an array been rotatedArrays, Data Structures
• Single element in a Sorted ArrayArrays, Binary Search, Data Structures
• Find peak elementArrays, Binary Search

4.2BS on Answers

• Find square root of a number in log nBinary Search, Data Structures
• Find the Nth root of a number using binary searchBinary Search, Data Structures
• Koko Eating BananasArrays, Binary Search, Data Structures
• Minimum days to make M bouquetsArrays, Binary Search, Data Structures
• Find the smallest DivisorMaths, Data Structures
• Capacity to Ship Packages within D DaysArrays, Binary Search, Data Structures
• Kth Missing Positive NumberArrays, Binary Search, Data Structures
• Aggressive CowsArrays, Binary Search, Data Structures
• Book Allocation ProblemArrays, Data Structures, Binary Search
• Split array - Largest SumArrays, Binary Search, Data Structures, Dynamic Programming
• Painter's partitionArrays, Binary Search, Data Structures
• Minimize Max Distance to Gas StationArrays, Binary Search, Data Structures
• Median of 2 sorted arraysArrays, Binary Search, Data Structures
• Kth element of 2 sorted arraysArrays, Data Structures

4.3BS on 2D Arrays

• Find the row with maximum number of 1'sArrays, Data Structures
• Search in a 2 D matrixBinary Search, Arrays, Data Structures
• Search in a row and column wise sorted matrixArrays, Binary Search, Data Structures
• Find Peak Element (2D Matrix)Arrays, Binary Search
• Matrix MedianBinary Search, Arrays, Data Structures

05Strings [Basic and Medium]

5.1Basic and Easy String Problems

• Remove outermost ParanthesisString, Stack
• Reverse words in a given string / Palindrome CheckTwo Pointer, String, Data Structures
• Largest odd number in a stringString, Data Structures
• Longest Common PrefixString, Data Structures
• Isomorphic StringString, Data Structures
• check whether one string is a rotation of anotherString, Data Structures
• Check if two strings are anagram of each otherString, Data Structures

5.2Medium String Problems

• Sort Characters by frequencyArrays, Hashing, Data Structures
• Maximum Nesting Depth of ParanthesisString, Stack
• Roman Number to Integer and vice versaHashing, Maths, String
• Implement AtoiString, Data Structures
• Count Number of SubstringsString, Data Structures
• Longest Palindromic Substring[Do it without DP]String, Data Structures
• Sum of Beauty of all substringHashing, Data Structures, String
• Reverse Every Word in A StringTwo Pointer, String, Data Structures

06Learn LinkedList [Single LL, Double LL, Medium, Hard Problems]

6.1Learn 1D LinkedList

• Introduction to LinkedList, learn about struct, and how is node representedLinked List, Data Structures
• Inserting a node in LinkedListLinked List, Data Structures
• Deleting a node in LinkedListLinked List, Data Structures
• Find the length of the linkedlist [learn traversal]Linked List, Data Structures
• Search an element in the LLLinked List, Data Structures

6.2Learn Doubly LinkedList

• Introduction to DLL, learn about struct, and how is node representedLinked List, Data Structures
• Insert a node in DLLLinked List, Data Structures
• Delete a node in DLLLinked List, Data Structures
• Reverse a DLLLinked List, Data Structures

6.3Medium Problems of LL

• Middle of a LinkedList [TortoiseHare Method]Linked List, Data Structures
• Reverse a LinkedList [Iterative]Linked List, Data Structures
• Reverse a LL [Recursive]Linked List, Data Structures
• Detect a loop in LLLinked List, Data Structures
• Find the starting point in LLLinked List, Hashing, Two Pointer, Data Structures
• Length of Loop in LLLinked List, Data Structures
• Check if LL is palindrome or notLinked List, Data Structures
• Segrregate odd and even nodes in LLLinked List, Data Structures
• Remove Nth node from the back of the LLLinked List, Two Pointer, Data Structures
• Delete the middle node of LLLinked List, Data Structures
• Sort LLLinked List, Data Structures
• Sort a LL of 0's 1's and 2's by changing linksArrays, Two Pointer, Data Structures
• Find the intersection point of Y LLLinked List, Data Structures
• Add 1 to a number represented by LLLinked List, Data Structures
• Add 2 numbers in LLLinked List, Data Structures

6.4Medium Problems of DLL

• Delete all occurrences of a key in DLLLinked List, Data Structures
• Find pairs with given sum in DLLLinked List, Data Structures
• Remove duplicates from sorted DLLLinked List, Data Structures

6.5Hard Problems of LL

• Reverse LL in group of given size KLinked List, Data Structures
• Rotate a LLLinked List, Data Structures
• Flattening of LLLinked List, Data Structures
• Clone a Linked List with random and next pointerLinked List, Data Structures

07Recursion [PatternWise]

7.1Get a Strong Hold

• Recursive Implementation of atoi()String, Recursion, Data Structures
• Pow(x, n)Maths, Recursion
• Count Good numbersMaths, Data Structures
• Sort a stack using recursionStack, Sorting, Data Structures
• Reverse a stack using recursionStack, Recursion, Data Structures

7.2Subsequences Pattern

• Generate all binary stringsString, Data Structures
• Generate ParanthesisString, Data Structures, Dynamic Programming
• Print all subsequences/Power SetRecursion, Data Structures
• Learn All Patterns of Subsequences (Theory)String, Data Structures
• Count all subsequences with sum KArrays, Hashing, Data Structures
• Check if there exists a subsequence with sum KArrays, Data Structures
• Combination SumRecursion, Data Structures, Arrays
• Combination Sum-IIRecursion, Data Structures, Arrays
• Subset Sum-IArrays, Recursion, Data Structures
• Subset Sum-IIArrays, Recursion, Data Structures
• Combination Sum - IIIRecursion, Data Structures, Arrays
• Letter Combinations of a Phone numberHashing, String, Data Structures

7.3Trying out all Combos / Hard

• Palindrome PartitioningString, Data Structures, Dynamic Programming
• Word SearchArrays, Data Structures, String
• N QueenArrays, Recursion
• Rat in a MazeRecursion, Data Structures
• Word Break
• M Coloring ProblemGraph, Data Structures
• Sudoko SolverArrays, Hashing, Data Structures
• Expression Add OperatorsMaths, String, Data Structures

08Bit Manipulation [Concepts & Problems]

8.1Learn Bit Manipulation

• Introduction to Bit Manipulation [Theory]Bit Manipulation, Data Structures
• Check if the i-th bit is set or notBit Manipulation
• Check if a number is odd or notMaths
• Check if a number is power of 2 or notMaths
• Count the number of set bitsBit Manipulation, Data Structures
• Set/Unset the rightmost unset bitBit Manipulation, Data Structures
• Swap two numbersMaths, Data Structures
• Divide two integers without using multiplication, division and mod operatorMaths, Data Structures

8.2Interview Problems

• Count number of bits to be flipped to convert A to BBit Manipulation
• Find the number that appears odd number of timesArrays, Hashing, Data Structures
• Power SetRecursion, Data Structures
• Find xor of numbers from L to RMaths, Data Structures
• Find the two numbers appearing odd number of timesArrays, Hashing, Data Structures

8.3Advanced Maths

• Print Prime Factors of a NumberMaths, Data Structures
• All Divisors of a NumberMaths, Data Structures
• Sieve of EratosthenesMaths, Data Structures
• Find Prime Factorisation of a Number using SieveMaths, Data Structures
• Power(n, x)Maths, Recursion, Data Structures

09Stack and Queues [Learning, Pre-In-Post-fix, Monotonic Stack, Implementation]

9.1Learning

• Implement Stack using ArraysStack, Arrays, Data Structures
• Implement Queue using ArraysArrays, Queue, Data Structures
• Implement Stack using QueueStack, Queue, Data Structures
• Implement Queue using StackQueue, Data Structures, Stack
• Implement stack using LinkedlistStack
• Implement queue using LinkedlistQueue, Linked List, Data Structures
• Check for balanced paranthesisStack, Data Structures
• Implement Min StackStack, Data Structures

9.2Prefix, Infix, PostFix Conversion Problems

• Infix to Postfix Conversion using StackStack, Data Structures
• Prefix to Infix ConversionStack, Data Structures
• Prefix to Postfix ConversionStack, Data Structures
• Postfix to Prefix ConversionStack, Data Structures
• Postfix to InfixStack, Data Structures
• Convert Infix To Prefix NotationStack, Data Structures

9.3Monotonic Stack/Queue Problems [VVV. Imp]

• Next Greater ElementArrays, Stack, Data Structures
• Next Greater Element 2Arrays, Stack, Data Structures
• Next Smaller ElementArrays, Stack, Data Structures
• Number of NGEs to the rightArrays, Hashing, Data Structures
• Trapping RainwaterArrays, Stack, Data Structures
• Sum of subarray minimumArrays, Dynamic Programming, Data Structures
• Asteroid CollisionArrays, Stack, Data Structures
• Sum of subarray rangesArrays, Stack, Data Structures
• Remove k DigitsString, Stack, Greedy
• Largest rectangle in a histogramArrays, Data Structures
• Maximal RectanglesArrays, Dynamic Programming, Stack, Data Structures

9.4Implementation Problems

• Sliding Window maximumQueue, Heap, Data Structures
• Stock span problemStack, Data Structures
• The Celebrity ProblemStack, Queue, Two Pointer, Data Structures
• LRU cache (IMPORTANT)Linked List, Data Structures
• LFU cacheLinked List, Data Structures

10Sliding Window & Two Pointer Combined Problems

10.1Medium Problems

• Longest Substring Without Repeating CharactersString, Data Structures
• Max Consecutive Ones IIIArrays, Binary Search, Data Structures
• Fruit Into BasketsArrays, Hashing, Data Structures
• longest repeating character replacementString, Hashing
• Binary subarray with sumArrays, Data Structures, Hashing
• Count number of nice subarraysArrays, Hashing, Maths
• Number of substring containing all three charactersHashing, String, Data Structures
• Maximum point you can obtain from cardsArrays, Data Structures

10.2Hard Problems

• Longest Substring with At Most K Distinct CharactersString, Data Structures
• Subarray with k different integersArrays, Hashing, Data Structures
• Minimum Window SubstringString, Data Structures
• Minimum Window SubsequenceString, Data Structures

11Heaps [Learning, Medium, Hard Problems]

11.1Learning

• Introduction to Priority Queues using Binary HeapsQueue, Heap
• Min Heap and Max Heap ImplementationHeap, Data Structures
• Check if an array represents a min-heap or notArrays, Heap, Data Structures
• Convert min Heap to max HeapHeap, Data Structures

11.2Medium Problems

• Kth largest element in an array [use priority queue]Arrays, Data Structures, Heap
• Kth smallest element in an array [use priority queue]Arrays, Heap, Data Structures
• Sort K sorted arrayArrays, Sorting, Data Structures
• Merge M sorted ListsArrays, Heap, Data Structures, Linked List
• Replace each array element by its corresponding rankArrays, Hashing, Data Structures
• Task SchedulerArrays, Hashing, Greedy, Sorting, Heap
• Hands of StraightsArrays, Hashing, Greedy, Sorting, Data Structures

11.3Hard Problems

• Design twitterHashing, Linked List, Heap
• Connect `n` ropes with minimal costArrays, Heap, Data Structures
• Kth largest element in a stream of running integersBinary Search Tree, Heap, Data Structures
• Maximum Sum CombinationArrays, Sorting, Heap, Data Structures
• Find Median from Data StreamTwo Pointer, Sorting, Heap, Data Structures
• K most frequent elementsArrays, Hashing, Sorting, Heap, Data Structures

12Greedy Algorithms [Easy, Medium/Hard]

12.1Easy Problems

• Assign CookiesArrays, Two Pointer, Greedy, Data Structures, Sorting
• Fractional Knapsack ProblemGreedy, Data Structures
• Greedy algorithm to find minimum number of coinsGreedy, Arrays, Data Structures
• Lemonade ChangeArrays, Greedy, Data Structures
• Valid Paranthesis CheckerStack, String, Data Structures

12.2Medium/Hard

• N meetings in one roomArrays, Greedy, Data Structures
• Jump GameArrays, Dynamic Programming, Greedy, Data Structures
• Jump Game 2Arrays, Dynamic Programming, Greedy, Data Structures
• Minimum number of platforms required for a railwayArrays, Greedy, Data Structures
• Job sequencing ProblemGreedy, Data Structures, Arrays
• CandyArrays, Greedy
• Program for Shortest Job First (or SJF) CPU SchedulingHashing, Data Structures
• Program for Least Recently Used (LRU) Page Replacement AlgorithmHashing, Data Structures
• Insert IntervalArrays, Data Structures
• Merge IntervalsArrays, Sorting, Data Structures
• Non-overlapping IntervalsArrays, Greedy, Sorting, Data Structures

13Binary Trees [Traversals, Medium and Hard Problems]

13.1Traversals

• Introduction to TreesBinary Tree, Data Structures
• Binary Tree Representation in C++Binary Tree, Data Structures
• Binary Tree Representation in JavaBinary Tree, Data Structures
• Binary Tree Traversals in Binary TreeBinary Tree, Data Structures
• Preorder Traversal of Binary TreeBinary Tree, Data Structures
• Inorder Traversal of Binary TreeBinary Tree, Data Structures
• Post-order Traversal of Binary TreeBinary Tree, Data Structures
• Level order Traversal / Level order traversal in spiral formBinary Tree, Data Structures
• Iterative Preorder Traversal of Binary TreeBinary Tree, Data Structures
• Iterative Inorder Traversal of Binary TreeBinary Tree, Data Structures
• Post-order Traversal of Binary Tree using 2 stackBinary Tree, Data Structures
• Post-order Traversal of Binary Tree using 1 stackBinary Tree, Data Structures
• Preorder, Inorder, and Postorder Traversal in one TraversalBinary Tree, Data Structures

13.2Medium Problems

• Height of a Binary TreeBinary Tree, Data Structures
• Check if the Binary tree is height-balanced or notBinary Tree, Data Structures
• Diameter of Binary TreeBinary Tree, Data Structures
• Maximum path sumBinary Tree, Data Structures
• Check if two trees are identical or notBinary Tree, Data Structures
• Zig Zag Traversal of Binary TreeBinary Tree, Data Structures
• Boundary Traversal of Binary TreeBinary Tree, Data Structures
• Vertical Order Traversal of Binary TreeBinary Tree, Data Structures
• Top View of Binary TreeBinary Tree, Data Structures
• Bottom View of Binary TreeBinary Tree, Data Structures
• Right/Left View of Binary TreeBinary Tree, Data Structures
• Symmetric Binary TreeBinary Tree, Data Structures

13.3Hard Problems

• Root to Node Path in Binary TreeBinary Tree, Data Structures
• LCA in Binary TreeBinary Search Tree, Data Structures
• Maximum width of a Binary TreeBinary Tree, Data Structures
• Check for Children Sum PropertyBinary Tree, Data Structures
• Print all the Nodes at a distance of K in a Binary TreeBinary Tree, Data Structures
• Minimum time taken to BURN the Binary Tree from a NodeBinary Tree, Data Structures
• Count total Nodes in a COMPLETE Binary TreeBinary Tree, Data Structures
• Requirements needed to construct a Unique Binary Tree | TheoryBinary Tree, Data Structures
• Construct Binary Tree from inorder and preorderBinary Tree, Data Structures
• Construct the Binary Tree from Postorder and Inorder TraversalBinary Tree, Data Structures
• Serialize and deserialize Binary TreeBinary Tree, Data Structures
• Morris Preorder Traversal of a Binary TreeBinary Tree, Data Structures
• Morris Inorder Traversal of a Binary TreeBinary Tree, Data Structures
• Flatten Binary Tree to LinkedListBinary Tree, Linked List, Data Structures

14Binary Search Trees [Concept and Problems]

14.1Concepts

• Introduction to Binary Search TreeBinary Search Tree
• Search in a Binary Search TreeBinary Search Tree, Data Structures
• Find Min/Max in BSTBinary Search Tree, Data Structures

14.2Practice Problems

• Ceil in a Binary Search TreeBinary Search Tree, Data Structures
• Floor in a Binary Search TreeBinary Search Tree, Data Structures
• Insert a given Node in Binary Search TreeBinary Search Tree, Data Structures
• Delete a Node in Binary Search TreeBinary Search Tree, Data Structures
• Find K-th smallest/largest element in BSTBinary Search Tree, Data Structures
• Check if a tree is a BST or BTBinary Tree, Data Structures
• LCA in Binary Search TreeBinary Search Tree, Data Structures
• Construct a BST from a preorder traversalBinary Search Tree, Data Structures
• Inorder Successor/Predecessor in BSTBinary Search Tree, Data Structures
• Merge 2 BST'sBinary Search Tree, Hashing, Data Structures
• Two Sum In BST | Check if there exists a pair with Sum KTwo Pointer, Binary Search Tree, Data Structures
• Recover BST | Correct BST with two nodes swappedBinary Search Tree, Data Structures
• Largest BST in Binary TreeBinary Search Tree, Binary Tree, Data Structures

15Graphs [Concepts & Problems]

15.1Learning

• Graph and TypesGraph, Data Structures
• Graph Representation | C++Graph, Data Structures
• Graph Representation | JavaGraph, Data Structures
• Connected Components | Logic ExplanationGraph, Data Structures
• BFSArrays, Graph, Data Structures
• DFSGraph, Data Structures

15.2Problems on BFS/DFS

• Number of provinces (leetcode)Graph, Data Structures
• Connected Components Problem in MatrixGraph, Data Structures
• Rotten OrangesStack, Graph, Data Structures
• Flood fillGraph, Data Structures
• Cycle Detection in unirected Graph (bfs)Graph, Data Structures
• Cycle Detection in undirected Graph (dfs)Data Structures, Graph
• 0/1 Matrix (Bfs Problem)Arrays, Graph, Data Structures
• Surrounded Regions (dfs)Graph, Data Structures
• Number of Enclaves [flood fill implementation - multisource]Graph, Data Structures
• Word ladder - 1Hashing, Data Structures, String
• Word ladder - 2Hashing, String, Data Structures
• Number of Distinct Islands [dfs multisource]Graph, Data Structures
• Bipartite Graph (DFS)Arrays, Graph, Data Structures
• Cycle Detection in Directed Graph (DFS)Data Structures, Graph

15.3Topo Sort and Problems

• Topo SortGraph, Data Structures
• Kahn's AlgorithmGraph, Data Structures
• Cycle Detection in Directed Graph (BFS)Data Structures, Graph
• Course Schedule - IGraph, Data Structures
• Course Schedule - IIGraph, Data Structures
• Find eventual safe statesGraph, Data Structures
• Alien dictionaryString, Data Structures

15.4Shortest Path Algorithms and Problems

• Shortest Path in UG with unit weightsGraph, Data Structures
• Shortest Path in DAGGraph, Data Structures
• Djisktra's AlgorithmGraph, Data Structures
• Why priority Queue is used in Djisktra's AlgorithmGraph, Data Structures
• Shortest path in a binary mazeArrays, Graph, Data Structures
• Path with minimum effortArrays, Binary Search, Heap, Graph, Data Structures
• Cheapest flights within k stopsGraph, Data Structures
• Network Delay timeGraph, Data Structures
• Number of ways to arrive at destinationGraph, Data Structures
• Minimum steps to reach end from start by performing multiplication and mod operations with array elementsGraph, Data Structures
• Bellman Ford AlgorithmGraph, Data Structures
• Floyd Warshal AlgorithmGraph, Data Structures
• Find the city with the smallest number of neighbors in a threshold distanceGraph, Data Structures

15.5MinimumSpanningTree/Disjoint Set and Problems

• Minimum Spanning TreeGraph, Data Structures
• Prim's AlgorithmGraph, Data Structures
• Disjoint Set [Union by Rank]Graph, Data Structures
• Disjoint Set [Union by Size]Graph, Data Structures
• Kruskal's AlgorithmGraph, Data Structures
• Number of operations to make network connectedGraph, Data Structures
• Most stones removed with same rows or columnsArrays, Data Structures, Graph
• Accounts mergeGraph, Data Structures
• Number of island IIGraph, Data Structures
• Making a Large IslandGraph, Data Structures
• Swim in rising waterArrays, Binary Search, Graph, Heap

15.6Other Algorithms

• Bridges in GraphGraph, Data Structures
• Articulation PointGraph, Data Structures
• Kosaraju's AlgorithmGraph, Data Structures

16Dynamic Programming [Patterns and Problems]

16.1Introduction to DP

• Dynamic Programming IntroductionDynamic Programming

16.21D DP

• Climbing StarsArrays, Dynamic Programming, Data Structures, Recursion
• Frog Jump(DP-3)Dynamic Programming, Arrays, Recursion, Data Structures
• Frog Jump with k distances(DP-4)Arrays, Dynamic Programming, Recursion, Data Structures
• Maximum sum of non-adjacent elements (DP 5)Arrays, Recursion, Data Structures, Dynamic Programming
• House Robber (DP 6)Arrays, Dynamic Programming, Recursion, Data Structures

16.32D/3D DP and DP on Grids

• Ninja's Training (DP 7)Arrays, Dynamic Programming, Data Structures, Recursion
• Grid Unique Paths : DP on Grids (DP8)Arrays, Recursion, Dynamic Programming, Data Structures
• Grid Unique Paths 2 (DP 9)Arrays, Recursion, Dynamic Programming, Data Structures
• Minimum path sum in Grid (DP 10)Arrays, Recursion, Dynamic Programming, Data Structures
• Minimum path sum in Triangular Grid (DP 11)Arrays, Dynamic Programming, Data Structures, Recursion
• Minimum/Maximum Falling Path Sum (DP-12)Arrays, Recursion, Dynamic Programming, Data Structures
• 3-d DP : Ninja and his friends (DP-13)Arrays, Recursion, Data Structures, Dynamic Programming

16.4DP on Subsequences

• Subset sum equal to target (DP- 14)Arrays, Data Structures, Dynamic Programming, Recursion
• Partition Equal Subset Sum (DP- 15)Arrays, Dynamic Programming, Recursion, Data Structures
• Partition Set Into 2 Subsets With Min Absolute Sum Diff (DP- 16)Arrays, Dynamic Programming, Data Structures, Recursion
• Count Subsets with Sum K (DP - 17)Arrays, Recursion, Data Structures, Dynamic Programming
• Count Partitions with Given Difference (DP - 18)Arrays, Recursion, Dynamic Programming, Data Structures
• Assign CookiesArrays, Dynamic Programming, Recursion, Data Structures
• Minimum Coins (DP - 20)Recursion, Arrays, Dynamic Programming, Data Structures
• Target Sum (DP - 21)Dynamic Programming, Data Structures, Arrays, Recursion
• Coin Change 2 (DP - 22)Arrays, Dynamic Programming, Data Structures, Recursion
• Unbounded Knapsack (DP - 23)Arrays, Data Structures, Dynamic Programming, Recursion
• Rod Cutting Problem | (DP - 24)Arrays, Dynamic Programming, Data Structures, Recursion

16.5DP on Strings

• Longest Common Subsequence | (DP - 25)Dynamic Programming, Arrays, Recursion, Data Structures
• Print Longest Common Subsequence | (DP - 26)Arrays, Data Structures, Dynamic Programming, Recursion
• Longest Common Substring | (DP - 27)Arrays, Dynamic Programming, Recursion, Data Structures
• Longest Palindromic Subsequence | (DP-28)Arrays, Recursion, Dynamic Programming, Data Structures
• Minimum insertions to make string palindrome | DP-29Arrays, Recursion, Dynamic Programming, Data Structures
• Minimum Insertions/Deletions to Convert String | (DP- 30)Arrays, Recursion, Dynamic Programming, Data Structures
• Shortest Common Supersequence | (DP - 31)Data Structures, Dynamic Programming, Recursion
• Distinct Subsequences| (DP-32)Arrays, Data Structures, Dynamic Programming, Recursion
• Edit Distance | (DP-33)Arrays, Data Structures, Dynamic Programming, Recursion
• Wildcard Matching | (DP-34)Data Structures, Dynamic Programming, Arrays, Recursion

16.6DP on Stocks

• Best Time to Buy and Sell Stock |(DP-35)Arrays, Data Structures, Recursion, Dynamic Programming
• Buy and Sell Stock - II|(DP-36)Arrays, Dynamic Programming, Recursion, Data Structures
• Buy and Sell Stocks III|(DP-37)Dynamic Programming, Arrays, Recursion, Data Structures
• Buy and Stock Sell IV |(DP-38)Arrays, Data Structures, Dynamic Programming, Recursion
• Buy and Sell Stocks With Cooldown|(DP-39)Arrays, Data Structures, Recursion, Dynamic Programming
• Buy and Sell Stocks With Transaction Fee|(DP-40)Arrays, Data Structures, Recursion, Dynamic Programming

16.7DP on LIS

• Longest Increasing Subsequence |(DP-41)Arrays, Recursion, Dynamic Programming, Data Structures
• Printing Longest Increasing Subsequence|(DP-42)Data Structures, Arrays, Dynamic Programming, Recursion
• Longest Increasing Subsequence |(DP-43)Arrays, Recursion, Dynamic Programming, Data Structures
• Largest Divisible Subset|(DP-44)Arrays, Recursion, Data Structures, Dynamic Programming
• Longest String Chain|(DP-45)String, Dynamic Programming, Data Structures, Recursion
• Longest Bitonic Subsequence |(DP-46)Arrays, Recursion, Data Structures, Dynamic Programming
• Number of Longest Increasing Subsequences|(DP-47)Arrays, Dynamic Programming, Graph, Data Structures

16.8MCM DP | Partition DP

• Matrix Chain Multiplication|(DP-48)Arrays, Dynamic Programming, Data Structures, Recursion
• Matrix Chain Multiplication | Bottom-Up|(DP-49)Arrays, Dynamic Programming, Recursion, Data Structures
• Minimum Cost to Cut the Stick|(DP-50)Arrays, Dynamic Programming, Data Structures, Recursion
• Burst Balloons|(DP-51)Arrays, Data Structures, Dynamic Programming, Recursion
• Evaluate Boolean Expression to True|(DP-52)String, Data Structures, Dynamic Programming, Recursion
• Palindrome Partitioning - II|(DP-53)String, Data Structures, Dynamic Programming
• Partition Array for Maximum Sum|(DP-54)Arrays, Dynamic Programming, Recursion, Data Structures

16.9DP on Squares

• Maximum Rectangle Area with all 1's|(DP-55)Arrays, Data Structures, Dynamic Programming, Recursion
• Count Square Submatrices with All Ones|(DP-56)Arrays, Data Structures, Recursion, Dynamic Programming

17Tries

17.1Theory

• Implement TRIE | INSERT | SEARCH | STARTSWITHTrie, Data Structures

17.2Problems

• Implement Trie - 2 (Prefix Tree)Trie, Data Structures
• Longest String with All PrefixesString, Data Structures
• Number of Distinct Substrings in a StringString, Trie, Data Structures
• Bit PreRequisites for TRIE ProblemsTrie, Data Structures
• Maximum XOR of two numbers in an arrayArrays, Hashing, Bit Manipulation, Data Structures, Trie
• Maximum XOR With an Element From ArrayArrays, Bit Manipulation, Trie, Data Structures

18Strings

18.1Hard Problems

• Minimum number of bracket reversals needed to make an expression balancedString, Stack, Two Pointer, Greedy
• Count and sayString, Data Structures
• Hashing In Strings | TheoryHashing, Data Structures
• Rabin KarpString, Data Structures
• Z-FunctionString, Data Structures
• KMP algo / LPS(pi) arrayString, Data Structures
• Shortest PalindromeString, Hashing, Data Structures
• Longest happy prefixString, Hashing
• Count palindromic subsequence in given stringString, Dynamic Programming, Data Structures