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Love Babbar
Love Babbar DSA Sheet
A broad topic-by-topic roadmap for interview practice.
448 practice entries · Source checked
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About this source edition
450-row original workbook
“Source checked” is when this edition was retrieved, not a claim that the creator updated it then.
Original sheet ↗Array
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Reverse the array | — | Open ↗ | — | |
| Find the maximum and minimum element in an array | — | Open ↗ | — | |
| Find the "Kth" max and min element of an array | — | Open ↗ | — | |
| Given an array which consists of only 0, 1 and 2. Sort the array without using any sorting algo | — | Open ↗ | — | |
| Move all the negative elements to one side of the array | — | Open ↗ | — | |
| Find the Union and Intersection of the two sorted arrays. | — | Open ↗ | — | |
| Write a program to cyclically rotate an array by one. | — | Open ↗ | — | |
| find Largest sum contiguous Subarray [V. IMP] | — | Open ↗ | — | |
| Minimise the maximum difference between heights [V.IMP] | — | Open ↗ | — | |
| Minimum no. of Jumps to reach end of an array | — | Open ↗ | — | |
| find duplicate in an array of N+1 Integers | — | Open ↗ | — | |
| Merge 2 sorted arrays without using Extra space. | — | Open ↗ | — | |
| Kadane's Algo [V.V.V.V.V IMP] | — | Open ↗ | — | |
| Merge Intervals | — | Open ↗ | — | |
| Next Permutation | — | Open ↗ | — | |
| Count Inversion | — | Open ↗ | — | |
| Best time to buy and Sell stock | — | Open ↗ | — | |
| find all pairs on integer array whose sum is equal to given number | — | Open ↗ | — | |
| find common elements In 3 sorted arrays | — | Open ↗ | — | |
| Rearrange the array in alternating positive and negative items with O(1) extra space | — | Open ↗ | — | |
| Find if there is any subarray with sum equal to 0 | — | Open ↗ | — | |
| Find factorial of a large number | — | Open ↗ | — | |
| find maximum product subarray | — | Open ↗ | — | |
| Find longest coinsecutive subsequence | — | Open ↗ | — | |
| Given an array of size n and a number k, fin all elements that appear more than " n/k " times. | — | Open ↗ | — | |
| Maximum profit by buying and selling a share atmost twice | — | Open ↗ | — | |
| Find whether an array is a subset of another array | — | Open ↗ | — | |
| Find the triplet that sum to a given value | — | Open ↗ | — | |
| Trapping Rain water problem | — | Open ↗ | — | |
| Chocolate Distribution problem | — | Open ↗ | — | |
| Smallest Subarray with sum greater than a given value | — | Open ↗ | — | |
| Three way partitioning of an array around a given value | — | Open ↗ | — | |
| Minimum swaps required bring elements less equal K together | — | Open ↗ | — | |
| Minimum no. of operations required to make an array palindrome | — | Open ↗ | — | |
| Median of 2 sorted arrays of equal size | — | Open ↗ | — | |
| Median of 2 sorted arrays of different size | — | Open ↗ | — |
Matrix
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Spiral traversal on a Matrix | — | Open ↗ | — | |
| Search an element in a matriix | — | Open ↗ | — | |
| Find median in a row wise sorted matrix | — | Open ↗ | — | |
| Find row with maximum no. of 1's | — | Open ↗ | — | |
| Print elements in sorted order using row-column wise sorted matrix | — | Open ↗ | — | |
| Maximum size rectangle | — | Open ↗ | — | |
| Find a specific pair in matrix | — | Open ↗ | — | |
| Rotate matrix by 90 degrees | — | Open ↗ | — | |
| Kth smallest element in a row-cpumn wise sorted matrix | — | Open ↗ | — | |
| Common elements in all rows of a given matrix | — | Open ↗ | — |
String
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Reverse a String | — | Open ↗ | — | |
| Check whether a String is Palindrome or not | — | Open ↗ | — | |
| Find Duplicate characters in a string | — | Open ↗ | — | |
| Why strings are immutable in Java? | — | See source ↗ | — | |
| Write a Code to check whether one string is a rotation of another | — | Open ↗ | — | |
| Write a Program to check whether a string is a valid shuffle of two strings or not | — | Open ↗ | — | |
| Count and Say problem | — | Open ↗ | — | |
| Write a program to find the longest Palindrome in a string.[ Longest palindromic Substring] | — | Open ↗ | — | |
| Find Longest Recurring Subsequence in String | — | Open ↗ | — | |
| Print all Subsequences of a string. | — | Open ↗ | — | |
| Print all the permutations of the given string | — | Open ↗ | — | |
| Split the Binary string into two substring with equal 0’s and 1’s | — | Open ↗ | — | |
| Word Wrap Problem [VERY IMP]. | — | Open ↗ | — | |
| EDIT Distance [Very Imp] | — | Open ↗ | — | |
| Find next greater number with same set of digits. [Very Very IMP] | — | Open ↗ | — | |
| Balanced Parenthesis problem.[Imp] | — | Open ↗ | — | |
| Word break Problem[ Very Imp] | — | Open ↗ | — | |
| Rabin Karp Algo | — | Open ↗ | — | |
| KMP Algo | — | Open ↗ | — | |
| Convert a Sentence into its equivalent mobile numeric keypad sequence. | — | Open ↗ | — | |
| Minimum number of bracket reversals needed to make an expression balanced. | — | Open ↗ | — | |
| Count All Palindromic Subsequence in a given String. | — | Open ↗ | — | |
| Count of number of given string in 2D character array | — | Open ↗ | — | |
| Search a Word in a 2D Grid of characters. | — | Open ↗ | — | |
| Boyer Moore Algorithm for Pattern Searching. | — | Open ↗ | — | |
| Converting Roman Numerals to Decimal | — | Open ↗ | — | |
| Longest Common Prefix | — | Open ↗ | — | |
| Number of flips to make binary string alternate | — | Open ↗ | — | |
| Find the first repeated word in string. | — | Open ↗ | — | |
| Minimum number of swaps for bracket balancing. | — | Open ↗ | — | |
| Find the longest common subsequence between two strings. | — | Open ↗ | — | |
| Program to generate all possible valid IP addresses from given string. | — | Open ↗ | — | |
| Write a program tofind the smallest window that contains all characters of string itself. | — | Open ↗ | — | |
| Rearrange characters in a string such that no two adjacent are same | — | Open ↗ | — | |
| Minimum characters to be added at front to make string palindrome | — | Open ↗ | — | |
| Given a sequence of words, print all anagrams together | — | Open ↗ | — | |
| Find the smallest window in a string containing all characters of another string | — | Open ↗ | — | |
| Recursively remove all adjacent duplicates | — | Open ↗ | — | |
| String matching where one string contains wildcard characters | — | Open ↗ | — | |
| Function to find Number of customers who could not get a computer | — | Open ↗ | — | |
| Transform One String to Another using Minimum Number of Given Operation | — | Open ↗ | — | |
| Check if two given strings are isomorphic to each other | — | Open ↗ | — | |
| Recursively print all sentences that can be formed from list of word lists | — | Open ↗ | — |
Searching & Sorting
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Find first and last positions of an element in a sorted array | — | Open ↗ | — | |
| Find a Fixed Point (Value equal to index) in a given array | — | Open ↗ | — | |
| Search in a rotated sorted array | — | Open ↗ | — | |
| square root of an integer | — | Open ↗ | — | |
| Maximum and minimum of an array using minimum number of comparisons | — | Open ↗ | — | |
| Optimum location of point to minimize total distance | — | Open ↗ | — | |
| Find the repeating and the missing | — | Open ↗ | — | |
| find majority element | — | Open ↗ | — | |
| Searching in an array where adjacent differ by at most k | — | Open ↗ | — | |
| find a pair with a given difference | — | Open ↗ | — | |
| find four elements that sum to a given value | — | Open ↗ | — | |
| maximum sum such that no 2 elements are adjacent | — | Open ↗ | — | |
| Count triplet with sum smaller than a given value | — | Open ↗ | — | |
| merge 2 sorted arrays | — | Open ↗ | — | |
| print all subarrays with 0 sum | — | Open ↗ | — | |
| Product array Puzzle | — | Open ↗ | — | |
| Sort array according to count of set bits | — | Open ↗ | — | |
| minimum no. of swaps required to sort the array | — | Open ↗ | — | |
| Bishu and Soldiers | — | Open ↗ | — | |
| Rasta and Kheshtak | — | Open ↗ | — | |
| Kth smallest number again | — | Open ↗ | — | |
| Find pivot element in a sorted array | — | Open ↗ | — | |
| K-th Element of Two Sorted Arrays | — | Open ↗ | — | |
| Aggressive cows | — | Open ↗ | — | |
| Book Allocation Problem | — | Open ↗ | — | |
| EKOSPOJ: | — | Open ↗ | — | |
| Job Scheduling Algo | — | Open ↗ | — | |
| Missing Number in AP | — | Open ↗ | — | |
| Smallest number with atleastn trailing zeroes infactorial | — | Open ↗ | — | |
| Painters Partition Problem: | — | Open ↗ | — | |
| ROTI-Prata SPOJ | — | Open ↗ | — | |
| DoubleHelix SPOJ | — | Open ↗ | — | |
| Subset Sums | — | Open ↗ | — | |
| Findthe inversion count | — | Open ↗ | — | |
| Implement Merge-sort in-place | — | Open ↗ | — | |
| Partitioning and Sorting Arrays with Many Repeated Entries | — | Open ↗ | — |
LinkedList
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Write a Program to reverse the Linked List. (Both Iterative and recursive) | — | Open ↗ | — | |
| Reverse a Linked List in group of Given Size. [Very Imp] | — | Open ↗ | — | |
| Write a program to Detect loop in a linked list. | — | Open ↗ | — | |
| Write a program to Delete loop in a linked list. | — | Open ↗ | — | |
| Find the starting point of the loop. | — | Open ↗ | — | |
| Remove Duplicates in a sorted Linked List. | — | Open ↗ | — | |
| Remove Duplicates in a Un-sorted Linked List. | — | Open ↗ | — | |
| Write a Program to Move the last element to Front in a Linked List. | — | Open ↗ | — | |
| Add “1” to a number represented as a Linked List. | — | Open ↗ | — | |
| Add two numbers represented by linked lists. | — | Open ↗ | — | |
| Intersection of two Sorted Linked List. | — | Open ↗ | — | |
| Intersection Point of two Linked Lists. | — | Open ↗ | — | |
| Merge Sort For Linked lists.[Very Important] | — | Open ↗ | — | |
| Quicksort for Linked Lists.[Very Important] | — | Open ↗ | — | |
| Find the middle Element of a linked list. | — | Open ↗ | — | |
| Check if a linked list is a circular linked list. | — | Open ↗ | — | |
| Split a Circular linked list into two halves. | — | Open ↗ | — | |
| Write a Program to check whether the Singly Linked list is a palindrome or not. | — | Open ↗ | — | |
| Deletion from a Circular Linked List. | — | Open ↗ | — | |
| Reverse a Doubly Linked list. | — | Open ↗ | — | |
| Find pairs with a given sum in a DLL. | — | Open ↗ | — | |
| Count triplets in a sorted DLL whose sum is equal to given value “X”. | — | Open ↗ | — | |
| Sort a “k”sorted Doubly Linked list.[Very IMP] | — | Open ↗ | — | |
| Rotate DoublyLinked list by N nodes. | — | Open ↗ | — | |
| Rotate a Doubly Linked list in group of Given Size.[Very IMP] | — | Open ↗ | — | |
| Can we reverse a linked list in less than O(n) ? | — | See source ↗ | — | |
| Why Quicksort is preferred for. Arrays and Merge Sort for LinkedLists ? | — | See source ↗ | — | |
| Flatten a Linked List | — | Open ↗ | — | |
| Sort a LL of 0's, 1's and 2's | — | Open ↗ | — | |
| Clone a linked list with next and random pointer | — | Open ↗ | — | |
| Merge K sorted Linked list | — | Open ↗ | — | |
| Multiply 2 no. represented by LL | — | Open ↗ | — | |
| Delete nodes which have a greater value on right side | — | Open ↗ | — | |
| Segregate even and odd nodes in a Linked List | — | Open ↗ | — | |
| Program for n’th node from the end of a Linked List | — | Open ↗ | — | |
| Find the first non-repeating character from a stream of characters | — | Open ↗ | — |
Binary Trees
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| level order traversal | — | Open ↗ | — | |
| Reverse Level Order traversal | — | Open ↗ | — | |
| Height of a tree | — | Open ↗ | — | |
| Diameter of a tree | — | Open ↗ | — | |
| Mirror of a tree | — | Open ↗ | — | |
| Inorder Traversal of a tree both using recursion and Iteration | — | Open ↗ | — | |
| Preorder Traversal of a tree both using recursion and Iteration | — | Open ↗ | — | |
| Postorder Traversal of a tree both using recursion and Iteration | — | Open ↗ | — | |
| Left View of a tree | — | Open ↗ | — | |
| Right View of Tree | — | Open ↗ | — | |
| Top View of a tree | — | Open ↗ | — | |
| Bottom View of a tree | — | Open ↗ | — | |
| Zig-Zag traversal of a binary tree | — | Open ↗ | — | |
| Check if a tree is balanced or not | — | Open ↗ | — | |
| Diagnol Traversal of a Binary tree | — | Open ↗ | — | |
| Boundary traversal of a Binary tree | — | Open ↗ | — | |
| Construct Binary Tree from String with Bracket Representation | — | Open ↗ | — | |
| Convert Binary tree into Doubly Linked List | — | Open ↗ | — | |
| Convert Binary tree into Sum tree | — | Open ↗ | — | |
| Construct Binary tree from Inorder and preorder traversal | — | Open ↗ | — | |
| Find minimum swaps required to convert a Binary tree into BST | — | Open ↗ | — | |
| Check if Binary tree is Sum tree or not | — | Open ↗ | — | |
| Check if all leaf nodes are at same level or not | — | Open ↗ | — | |
| Check if a Binary Tree contains duplicate subtrees of size 2 or more [ IMP ] | — | Open ↗ | — | |
| Check if 2 trees are mirror or not | — | Open ↗ | — | |
| Sum of Nodes on the Longest path from root to leaf node | — | Open ↗ | — | |
| Check if given graph is tree or not. [ IMP ] | — | Open ↗ | — | |
| Find Largest subtree sum in a tree | — | Open ↗ | — | |
| Maximum Sum of nodes in Binary tree such that no two are adjacent | — | Open ↗ | — | |
| Print all "K" Sum paths in a Binary tree | — | Open ↗ | — | |
| Find LCA in a Binary tree | — | Open ↗ | — | |
| Find distance between 2 nodes in a Binary tree | — | Open ↗ | — | |
| Kth Ancestor of node in a Binary tree | — | Open ↗ | — | |
| Find all Duplicate subtrees in a Binary tree [ IMP ] | — | Open ↗ | — | |
| Tree Isomorphism Problem | — | Open ↗ | — |
Binary Search Trees
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Fina a value in a BST | — | Open ↗ | — | |
| Deletion of a node in a BST | — | Open ↗ | — | |
| Find min and max value in a BST | — | Open ↗ | — | |
| Find inorder successor and inorder predecessor in a BST | — | Open ↗ | — | |
| Check if a tree is a BST or not | — | Open ↗ | — | |
| Populate Inorder successor of all nodes | — | Open ↗ | — | |
| Find LCA of 2 nodes in a BST | — | Open ↗ | — | |
| Construct BST from preorder traversal | — | Open ↗ | — | |
| Convert Binary tree into BST | — | Open ↗ | — | |
| Convert a normal BST into a Balanced BST | — | Open ↗ | — | |
| Merge two BST [ V.V.V>IMP ] | — | Open ↗ | — | |
| Find Kth largest element in a BST | — | Open ↗ | — | |
| Find Kth smallest element in a BST | — | Open ↗ | — | |
| Count pairs from 2 BST whose sum is equal to given value "X" | — | Open ↗ | — | |
| Find the median of BST in O(n) time and O(1) space | — | Open ↗ | — | |
| Count BST ndoes that lie in a given range | — | Open ↗ | — | |
| Replace every element with the least greater element on its right | — | Open ↗ | — | |
| Given "n" appointments, find the conflicting appointments | — | Open ↗ | — | |
| Check preorder is valid or not | — | Open ↗ | — | |
| Check whether BST contains Dead end | — | Open ↗ | — | |
| Largest BST in a Binary Tree [ V.V.V.V.V IMP ] | — | Open ↗ | — | |
| Flatten BST to sorted list | — | Open ↗ | — |
Greedy
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Activity Selection Problem | — | Open ↗ | — | |
| Job SequencingProblem | — | Open ↗ | — | |
| Huffman Coding | — | Open ↗ | — | |
| Water Connection Problem | — | Open ↗ | — | |
| Fractional Knapsack Problem | — | Open ↗ | — | |
| Greedy Algorithm to find Minimum number of Coins | — | Open ↗ | — | |
| Maximum trains for which stoppage can be provided | — | Open ↗ | — | |
| Minimum Platforms Problem | — | Open ↗ | — | |
| Buy Maximum Stocks if i stocks can be bought on i-th day | — | Open ↗ | — | |
| Find the minimum and maximum amount to buy all N candies | — | Open ↗ | — | |
| Minimize Cash Flow among a given set of friends who have borrowed money from each other | — | Open ↗ | — | |
| Minimum Cost to cut a board into squares | — | Open ↗ | — | |
| Check if it is possible to survive on Island | — | Open ↗ | — | |
| Find maximum meetings in one room | — | Open ↗ | — | |
| Maximum product subset of an array | — | Open ↗ | — | |
| Maximize array sum after K negations | — | Open ↗ | — | |
| Maximize the sum of arr[i]*i | — | Open ↗ | — | |
| Maximum sum of absolute difference of an array | — | Open ↗ | — | |
| Maximize sum of consecutive differences in a circular array | — | Open ↗ | — | |
| Minimum sum of absolute difference of pairs of two arrays | — | Open ↗ | — | |
| Program for Shortest Job First (or SJF) CPU Scheduling | — | Open ↗ | — | |
| Program for Least Recently Used (LRU) Page Replacement algorithm | — | Open ↗ | — | |
| Smallest subset with sum greater than all other elements | — | Open ↗ | — | |
| Chocolate Distribution Problem | — | Open ↗ | — | |
| DEFKIN -Defense of a Kingdom | — | Open ↗ | — | |
| DIEHARD -DIE HARD | — | Open ↗ | — | |
| GERGOVIA -Wine trading in Gergovia | — | Open ↗ | — | |
| Picking Up Chicks | — | Open ↗ | — | |
| CHOCOLA –Chocolate | — | Open ↗ | — | |
| ARRANGE -Arranging Amplifiers | — | Open ↗ | — | |
| K Centers Problem | — | Open ↗ | — | |
| Minimum Cost of ropes | — | Open ↗ | — | |
| Find smallest number with given number of digits and sum of digits | — | Open ↗ | — | |
| Rearrange characters in a string such that no two adjacent are same | — | Open ↗ | — | |
| Find maximum sum possible equal sum of three stacks | — | Open ↗ | — |
BackTracking
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Rat in a maze Problem | — | Open ↗ | — | |
| Printing all solutions in N-Queen Problem | — | Open ↗ | — | |
| Word Break Problem using Backtracking | — | Open ↗ | — | |
| Remove Invalid Parentheses | — | Open ↗ | — | |
| Sudoku Solver | — | Open ↗ | — | |
| m Coloring Problem | — | Open ↗ | — | |
| Print all palindromic partitions of a string | — | Open ↗ | — | |
| Subset Sum Problem | — | Open ↗ | — | |
| The Knight’s tour problem | — | Open ↗ | — | |
| Tug of War | — | Open ↗ | — | |
| Find shortest safe route in a path with landmines | — | Open ↗ | — | |
| Combinational Sum | — | Open ↗ | — | |
| Find Maximum number possible by doing at-most K swaps | — | Open ↗ | — | |
| Print all permutations of a string | — | Open ↗ | — | |
| Find if there is a path of more than k length from a source | — | Open ↗ | — | |
| Longest Possible Route in a Matrix with Hurdles | — | Open ↗ | — | |
| Print all possible paths from top left to bottom right of a mXn matrix | — | Open ↗ | — | |
| Partition of a set intoK subsets with equal sum | — | Open ↗ | — | |
| Find the K-th Permutation Sequence of first N natural numbers | — | Open ↗ | — |
Stacks & Queues
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Implement Stack from Scratch | — | Open ↗ | — | |
| Implement Queue from Scratch | — | Open ↗ | — | |
| Implement 2 stack in an array | — | Open ↗ | — | |
| find the middle element of a stack | — | Open ↗ | — | |
| Implement "N" stacks in an Array | — | Open ↗ | — | |
| Check the expression has valid or Balanced parenthesis or not. | — | Open ↗ | — | |
| Reverse a String using Stack | — | Open ↗ | — | |
| Design a Stack that supports getMin() in O(1) time and O(1) extra space. | — | Open ↗ | — | |
| Find the next Greater element | — | Open ↗ | — | |
| The celebrity Problem | — | Open ↗ | — | |
| Arithmetic Expression evaluation | — | Open ↗ | — | |
| Evaluation of Postfix expression | — | Open ↗ | — | |
| Implement a method to insert an element at its bottom without using any other data structure. | — | Open ↗ | — | |
| Reverse a stack using recursion | — | Open ↗ | — | |
| Sort a Stack using recursion | — | Open ↗ | — | |
| Merge Overlapping Intervals | — | Open ↗ | — | |
| Largest rectangular Area in Histogram | — | Open ↗ | — | |
| Length of the Longest Valid Substring | — | Open ↗ | — | |
| Expression contains redundant bracket or not | — | Open ↗ | — | |
| Implement Stack using Queue | — | Open ↗ | — | |
| Implement Stack using Deque | — | Open ↗ | — | |
| Stack Permutations (Check if an array is stack permutation of other) | — | Open ↗ | — | |
| Implement Queue using Stack | — | Open ↗ | — | |
| Implement "n" queue in an array | — | Open ↗ | — | |
| Implement a Circular queue | — | Open ↗ | — | |
| LRU Cache Implementationa | — | Open ↗ | — | |
| Reverse a Queue using recursion | — | Open ↗ | — | |
| Reverse the first “K” elements of a queue | — | Open ↗ | — | |
| Interleave the first half of the queue with second half | — | Open ↗ | — | |
| Find the first circular tour that visits all Petrol Pumps | — | Open ↗ | — | |
| Minimum time required to rot all oranges | — | Open ↗ | — | |
| Distance of nearest cell having 1 in a binary matrix | — | Open ↗ | — | |
| First negative integer in every window of size “k” | — | Open ↗ | — | |
| Check if all levels of two trees are anagrams or not. | — | Open ↗ | — | |
| Sum of minimum and maximum elements of all subarrays of size “k”. | — | Open ↗ | — | |
| Minimum sum of squares of character counts in a given string after removing “k” characters. | — | Open ↗ | — | |
| Queue based approach or first non-repeating character in a stream. | — | Open ↗ | — | |
| Next Smaller Element | — | Open ↗ | — |
Heap
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Implement a Maxheap/MinHeap using arrays and recursion. | — | Open ↗ | — | |
| Sort an Array using heap. (HeapSort) | — | Open ↗ | — | |
| Maximum of all subarrays of size k. | — | Open ↗ | — | |
| “k” largest element in an array | — | Open ↗ | — | |
| Kth smallest and largest element in an unsorted array | — | Open ↗ | — | |
| Merge “K” sorted arrays. [ IMP ] | — | Open ↗ | — | |
| Merge 2 Binary Max Heaps | — | Open ↗ | — | |
| Kth largest sum continuous subarrays | — | Open ↗ | — | |
| Leetcode- reorganize strings | — | Open ↗ | — | |
| Merge “K” Sorted Linked Lists [V.IMP] | — | Open ↗ | — | |
| Smallest range in “K” Lists | — | Open ↗ | — | |
| Median in a stream of Integers | — | Open ↗ | — | |
| Check if a Binary Tree is Heap | — | Open ↗ | — | |
| Connect “n” ropes with minimum cost | — | Open ↗ | — | |
| Convert BST to Min Heap | — | Open ↗ | — | |
| Convert min heap to max heap | — | Open ↗ | — | |
| Rearrange characters in a string such that no two adjacent are same. | — | Open ↗ | — | |
| Minimum sum of two numbers formed from digits of an array | — | Open ↗ | — |
Graph
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Create a Graph, print it | — | Open ↗ | — | |
| Implement BFS algorithm | — | Open ↗ | — | |
| Implement DFS Algo | — | Open ↗ | — | |
| Detect Cycle in Directed Graph using BFS/DFS Algo | — | Open ↗ | — | |
| Detect Cycle in UnDirected Graph using BFS/DFS Algo | — | Open ↗ | — | |
| Search in a Maze | — | Open ↗ | — | |
| Minimum Step by Knight | — | Open ↗ | — | |
| flood fill algo | — | Open ↗ | — | |
| Clone a graph | — | Open ↗ | — | |
| Making wired Connections | — | Open ↗ | — | |
| word Ladder | — | Open ↗ | — | |
| Dijkstra algo | — | Open ↗ | — | |
| Implement Topological Sort | — | Open ↗ | — | |
| Minimum time taken by each job to be completed given by a Directed Acyclic Graph | — | Open ↗ | — | |
| Find whether it is possible to finish all tasks or not from given dependencies | — | Open ↗ | — | |
| Find the no. of Isalnds | — | Open ↗ | — | |
| Given a sorted Dictionary of an Alien Language, find order of characters | — | Open ↗ | — | |
| Implement Kruksal’sAlgorithm | — | Open ↗ | — | |
| Implement Prim’s Algorithm | — | Open ↗ | — | |
| Total no. of Spanning tree in a graph | — | Open ↗ | — | |
| Implement Bellman Ford Algorithm | — | Open ↗ | — | |
| Implement Floyd warshallAlgorithm | — | Open ↗ | — | |
| Travelling Salesman Problem | — | Open ↗ | — | |
| Graph ColouringProblem | — | Open ↗ | — | |
| Snake and Ladders Problem | — | Open ↗ | — | |
| Find bridge in a graph | — | Open ↗ | — | |
| Count Strongly connected Components(Kosaraju Algo) | — | Open ↗ | — | |
| Check whether a graph is Bipartite or Not | — | Open ↗ | — | |
| Detect Negative cycle in a graph | — | Open ↗ | — | |
| Longest path in a Directed Acyclic Graph | — | Open ↗ | — | |
| Journey to the Moon | — | Open ↗ | — | |
| Cheapest Flights Within K Stops | — | Open ↗ | — | |
| Oliver and the Game | — | Open ↗ | — | |
| Water Jug problem using BFS | — | Open ↗ | — | |
| Water Jug problem using BFS | — | Open ↗ | — | |
| Find if there is a path of more thank length from a source | — | Open ↗ | — | |
| M-ColouringProblem | — | Open ↗ | — | |
| Minimum edges to reverse o make path from source to destination | — | Open ↗ | — | |
| Paths to travel each nodes using each edge(Seven Bridges) | — | Open ↗ | — | |
| Vertex Cover Problem | — | Open ↗ | — | |
| Chinese Postman or Route Inspection | — | Open ↗ | — | |
| Number of Triangles in a Directed and Undirected Graph | — | Open ↗ | — | |
| Minimise the cashflow among a given set of friends who have borrowed money from each other | — | Open ↗ | — | |
| Two Clique Problem | — | Open ↗ | — |
Trie
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Construct a trie from scratch | — | Open ↗ | — | |
| Find shortest unique prefix for every word in a given list | — | Open ↗ | — | |
| Word Break Problem | (Trie solution) | — | Open ↗ | — | |
| Given a sequence of words, print all anagrams together | — | Open ↗ | — | |
| Implement a Phone Directory | — | Open ↗ | — | |
| Print unique rows in a given boolean matrix | — | Open ↗ | — |
Dynamic Programming
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Coin ChangeProblem | — | Open ↗ | — | |
| Knapsack Problem | — | Open ↗ | — | |
| Binomial CoefficientProblem | — | Open ↗ | — | |
| Permutation CoefficientProblem | — | Open ↗ | — | |
| Program for nth Catalan Number | — | Open ↗ | — | |
| Matrix Chain Multiplication | — | Open ↗ | — | |
| Edit Distance | — | Open ↗ | — | |
| Subset Sum Problem | — | Open ↗ | — | |
| Friends Pairing Problem | — | Open ↗ | — | |
| Gold Mine Problem | — | Open ↗ | — | |
| Assembly Line SchedulingProblem | — | Open ↗ | — | |
| Painting the Fenceproblem | — | Open ↗ | — | |
| Maximize The Cut Segments | — | Open ↗ | — | |
| Longest Common Subsequence | — | Open ↗ | — | |
| Longest Repeated Subsequence | — | Open ↗ | — | |
| Longest Increasing Subsequence | — | Open ↗ | — | |
| Space Optimized Solution of LCS | — | Open ↗ | — | |
| LCS (Longest Common Subsequence) of three strings | — | Open ↗ | — | |
| Maximum Sum Increasing Subsequence | — | Open ↗ | — | |
| Count all subsequences having product less than K | — | Open ↗ | — | |
| Longest subsequence such that difference between adjacent is one | — | Open ↗ | — | |
| Maximum subsequence sum such that no three are consecutive | — | Open ↗ | — | |
| Egg Dropping Problem | — | Open ↗ | — | |
| Maximum Length Chain of Pairs | — | Open ↗ | — | |
| Maximum size square sub-matrix with all 1s | — | Open ↗ | — | |
| Maximum sum of pairs with specific difference | — | Open ↗ | — | |
| Min Cost PathProblem | — | Open ↗ | — | |
| Maximum difference of zeros and ones in binary string | — | Open ↗ | — | |
| Minimum number of jumps to reach end | — | Open ↗ | — | |
| Minimum cost to fill given weight in a bag | — | Open ↗ | — | |
| Minimum removals from array to make max –min <= K | — | Open ↗ | — | |
| Longest Common Substring | — | Open ↗ | — | |
| Count number of ways to reacha given score in a game | — | Open ↗ | — | |
| Count Balanced Binary Trees of Height h | — | Open ↗ | — | |
| LargestSum Contiguous Subarray [V>V>V>V IMP ] | — | Open ↗ | — | |
| Smallest sum contiguous subarray | — | Open ↗ | — | |
| Unbounded Knapsack (Repetition of items allowed) | — | Open ↗ | — | |
| Word Break Problem | — | Open ↗ | — | |
| Largest Independent Set Problem | — | Open ↗ | — | |
| Partition problem | — | Open ↗ | — | |
| Longest Palindromic Subsequence | — | Open ↗ | — | |
| Count All Palindromic Subsequence in a given String | — | Open ↗ | — | |
| Longest Palindromic Substring | — | Open ↗ | — | |
| Longest alternating subsequence | — | Open ↗ | — | |
| Weighted Job Scheduling | — | Open ↗ | — | |
| Coin game winner where every player has three choices | — | Open ↗ | — | |
| Count Derangements (Permutation such that no element appears in its original position) [ IMPORTANT ] | — | Open ↗ | — | |
| Maximum profit by buying and selling a share at most twice [ IMP ] | — | Open ↗ | — | |
| Optimal Strategy for a Game | — | Open ↗ | — | |
| Optimal Binary Search Tree | — | Open ↗ | — | |
| Palindrome PartitioningProblem | — | Open ↗ | — | |
| Word Wrap Problem | — | Open ↗ | — | |
| Mobile Numeric Keypad Problem [ IMP ] | — | Open ↗ | — | |
| Boolean Parenthesization Problem | — | Open ↗ | — | |
| Largest rectangular sub-matrix whose sum is 0 | — | Open ↗ | — | |
| Largest area rectangular sub-matrix with equal number of 1’s and 0’s [ IMP ] | — | Open ↗ | — | |
| Maximum sum rectangle in a 2D matrix | — | Open ↗ | — | |
| Maximum profit by buying and selling a share at most k times | — | Open ↗ | — | |
| Find if a string is interleaved of two other strings | — | Open ↗ | — | |
| Maximum Length of Pair Chain | — | Open ↗ | — |
Bit Manipulation
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| Done | Problem | Level | Practice | Video |
|---|---|---|---|---|
| Count set bits in an integer | — | Open ↗ | — | |
| Find the two non-repeating elements in an array of repeating elements | — | Open ↗ | — | |
| Count number of bits to be flipped to convert A to B | — | Open ↗ | — | |
| Count total set bits in all numbers from 1 to n | — | Open ↗ | — | |
| Program to find whether a no is power of two | — | Open ↗ | — | |
| Find position of the only set bit | — | Open ↗ | — | |
| Copy set bits in a range | — | Open ↗ | — | |
| Divide two integers without using multiplication, division and mod operator | — | Open ↗ | — | |
| Calculate square of a number without using *, / and pow() | — | Open ↗ | — | |
| Power Set | — | Open ↗ | — |