DSA Sheet by Love Babbar

Last Updated : 06 Oct, 2023

Who is Love Babbar?

Love Babbar is a famous Youtuber, graduated from NSUT Delhi who has also worked as a Software Engineer at Amazon.

What is a DSA Sheet?

A sheet that covers almost every concept of Data Structures and Algorithms.

DSA Sheet

So, this DSA sheet by Love Babbar contains 450 coding questions which will help in:

Understanding each and every concept of DSA.
Clearing the DSA round for the Interviews, as these are the questions generally asked in the companies like Amazon, Microsoft, Google, etc.
Basic Knowledge of Data Structures and Algorithms.
Having good knowledge of at-least one programming knowledge like C++, Java, Python.
Know how to use STL as it will make data structures and few techniques easier to implement.

Below is the topic-wise distribution of 450 questions:

Arrays(36)
Matrix(10)
Strings(43)
Searching and Sorting(36)
Linked List(36)
Bit Manipulation(10)
Greedy(35)
Backtracking(19)

Dynamic Programming(60)
Stacks and Queues(38)
Binary Trees(35)
Binary Search Tree(22)
Graphs(44)
Heap(18)
Trie(6)

This sheet can be completed within 2-3 months without any cheat day. So, Start solving this 450 DSA Cracker from today itself. Keep a track of all the problems mentioned below: Practice Love Babbar DSA Sheet

Arrays

Question	Article	Practice
Reverse an Array/String	Link	Link
Find the maximum and minimum element in an array	Link	Link
Find the “Kth” max and min element of an array	Link	Link
Given an array which consists of only 0, 1 and 2. Sort the array without using any sorting algo	Link	Link
Move all the negative elements to one side of the array	Link	Link
Find the Union and Intersection of the two sorted arrays.	Link	Link
Write a program to cyclically rotate an array by one.	Link	Link
Find Largest sum contiguous Subarray [V. IMP]	Link	Link
Minimize the maximum difference between heights [V.IMP]	Link	Link
Minimum no. of Jumps to reach end of an array	Link	Link
Find duplicate in an array of N+1 Integers	Link	Link
Merge 2 sorted arrays without using Extra space.	Link	Link
Kadane’s Algo [V.V.V.V.V IMP]	Link	Link
Merge Intervals	Link	Link
Next Permutation	Link	Link
Count Inversion	Link	Link
Best time to buy and Sell stock	Link	Link
Find all pairs on integer array whose sum is equal to given number	Link	Link
Find common elements In 3 sorted arrays	Link	Link
Rearrange the array in alternating positive and negative items with O(1) extra space	Link	Link
Find if there is any subarray with sum equal to 0	Link	Link
Find factorial of a large number	Link	Link
Find maximum product subarray	Link	Link
Find longest consecutive subsequence	Link	Link
Given an array of size n and a number k, fin all elements that appear more than ” n/k ” times.	Link	Link
Maximum profit by buying and selling a share at most twice	Link	Link
Find whether an array is a subset of another array	Link	Link
Find the triplet that sum to a given value	Link	Link
Trapping Rain water problem	Link	Link
Chocolate Distribution problem	Link	Link
Smallest Subarray with sum greater than a given value	Link	Link
Three way partitioning of an array around a given value	Link	Link
Minimum swaps required bring elements less equal K together	Link	Link
Minimum no. of operations required to make an array palindrome	Link	Link
Median of 2 sorted arrays of equal size	Link	Link
Median of 2 sorted arrays of different size	Link	Link

Matrix

Question	Article	Practice
Spiral traversal on a Matrix	Link	LInk
Search an element in a Matrix	Link	Link
Find median in a row wise sorted matrix	Link	Link
Find row with maximum no. of 1’s	Link	Link
Print elements in sorted order using row-column wise sorted matrix	Link	Link
Maximum size rectangle	Link	Link
Find a specific pair in matrix	Link	NA
Rotate matrix by 90 degrees	Link	Link
Kth smallest element in a row-column wise sorted matrix	Link	Link
Common elements in all rows of a given matrix	Link	Link

Strings

Question	Article	Practice
Reverse a String	Link	Link
Check whether a String is Palindrome or not	Link	Link
Find Duplicate characters in a string	Link	NA
Why strings are immutable in Java?	Link	NA
Write a Code to check whether one string is a rotation of another	Link	Link
Write a Program to check whether a string is a valid shuffle of two strings or not	Link	NA
Count and Say problem	Link	Link
Write a program to find the longest Palindrome in a string.[ Longest palindromic Substring]	Link	Link
Find Longest Recurring Subsequence in String	Link	Link
Print all Subsequences of a string.	Link	NA
Print all the permutations of the given string	Link	Link
Split the Binary string into two substring with equal 0’s and 1’s	Link	NA
Word Wrap Problem [VERY IMP].	Link	Link
EDIT Distance [Very Imp]	Link	Link
Find next greater number with same set of digits. [Very Very IMP]	Link	Link
Balanced Parenthesis problem.[Imp]	Link	Link
Word break Problem[ Very Imp]	Link	Link
Rabin Karp Algorithm	Link	Link
KMP Algorithm	Link	Link
Convert a Sentence into its equivalent mobile numeric keypad sequence.	Link	Link
Minimum number of bracket reversals needed to make an expression balanced.	Link	Link
Count All Palindromic Subsequence in a given String.	Link	Link
Count of number of given string in 2D character array	Link	Link
Search a Word in a 2D Grid of characters.	Link	Link
Boyer Moore Algorithm for Pattern Searching.	Link	Link
Converting Roman Numerals to Decimal	Link	Link
Longest Common Prefix	Link	Link
Number of flips to make binary string alternate	Link	Link
Find the first repeated word in string.	Link	Link
Minimum number of swaps for bracket balancing.	Link	Link
Find the longest common subsequence between two strings.	Link	Link
Program to generate all possible valid IP addresses from given string.	Link	Link
Write a program to find the smallest window that contains all characters of string itself.	Link	Link
Rearrange characters in a string such that no two adjacent are same	Link	Link
Minimum characters to be added at front to make string palindrome	Link	Link
Given a sequence of words, print all anagrams together	Link	Link
Find the smallest window in a string containing all characters of another string	Link	Link
Recursively remove all adjacent duplicates	Link	Link
String matching where one string contains wildcard characters	Link	Link
Function to find Number of customers who could not get a computer	Link	NA
Transform One String to Another using Minimum Number of Given Operation	Link	Link
Check if two given strings are isomorphic to each other	Link	Link
Recursively print all sentences that can be formed from list of word lists	Link	NA

Searching and Sorting:

Question	Article	Practice
Find first and last positions of an element in a sorted array	Link	Link
Find a Fixed Point (Value equal to index) in a given array	Link	Link
Search in a rotated sorted array	Link	Link
Square root of an integer	Link	Link
Maximum and minimum of an array using minimum number of comparisons	Link	Link
Optimum location of point to minimize total distance	Link	Link
Find the repeating and the missing	Link	Link
Find majority element	Link	Link
Searching in an array where adjacent differ by at most k	Link	Link
Find a pair with a given difference	Link	Link
Find four elements that sum to a given value	Link	Link
Maximum sum such that no 2 elements are adjacent	Link	Link
Count triplet with sum smaller than a given value	Link	Link
Merge 2 sorted arrays	Link	Link
Product array Puzzle	Link	Link
Sort array according to count of set bits	Link	Link
Minimum no. of swaps required to sort the array	Link	Link
Bishu and Soldiers	Link	Link
Rasta and Kheshtak	Link	Link
Kth smallest number again	Link	Link
Find pivot element in a sorted array	Link	Link
K-th Element of Two Sorted Arrays	Link	Link
Aggressive cows	Link	Link
Book Allocation Problem	Link	Link
EKOSPOJ:	Link	Link
Job Scheduling Algo	Link	Link
Missing Number in AP	Link	Link
Smallest number with atleast n trailing zeroes in factorial	Link	Link
Painters Partition Problem:	Link	Link
ROTI-Prata SPOJ	Link	Link
DoubleHelix SPOJ	Link	Link
Subset Sums	Link	Link
Find the inversion count	Link	Link
Implement Merge-sort in-place	Link	Link
Partitioning and Sorting Arrays with Many Repeated Entries	Link	Link

LinkedList:

Question	Article	Practice
Write a Program to reverse the Linked List. (Both Iterative and recursive)	Link	Link
Reverse a Linked List in group of Given Size. [Very Imp]	Link	Link
Write a program to Detect loop in a linked list.	Link	Link
Write a program to Delete loop in a linked list.	Link	Link
Find the starting point of the loop.	Link	Link
Remove Duplicates in a sorted Linked List.	Link	Link
Remove Duplicates in a Un-sorted Linked List.	Link	Link
Write a Program to Move the last element to Front in a Linked List.	Link	Link
Add “1” to a number represented as a Linked List.	Link	Link
Add two numbers represented by linked lists.	Link	Link
Intersection of two Sorted Linked List.	Link	Link
Intersection Point of two Linked Lists.	Link	Link
Merge Sort For Linked lists.[Very Important]	Link	Link
Quicksort for Linked Lists.[Very Important]	Link	Link
Find the middle Element of a linked list.	Link	Link
Check if a linked list is a circular linked list.	Link	Link
Split a Circular linked list into two halves.	Link	Link
Write a Program to check whether the Singly Linked list is a palindrome or not.	Link	Link
Deletion from a Circular Linked List.	Link	Link
Reverse a Doubly Linked list.	Link	Link
Find pairs with a given sum in a DLL.	Link	Link
Count triplets in a sorted DLL whose sum is equal to given value “X”.	Link	Link
Sort a “k”sorted Doubly Linked list.[Very IMP]	Link	Link
Rotate Doubly Linked list by N nodes.	Link	Link
Rotate a Doubly Linked list in group of Given Size.[Very IMP]	Link	Link
Can we reverse a linked list in less than O(n) ?	Link	Link
Why Quicksort is preferred for. Arrays and Merge Sort for Linked Lists ?	Link	Link
Flatten a Linked List	Link	Link
Sort a LL of 0’s, 1’s and 2’s	Link	Link
Clone a linked list with next and random pointer	Link	Link
Merge K sorted Linked list	Link	Link
Multiply 2 no. represented by LL	Link	Link
Delete nodes which have a greater value on right side	Link	Link
Segregate even and odd nodes in a Linked List	Link	Link
Program for n’th node from the end of a Linked List	Link	Link

Bit Manipulation:

Question	Article	Practice
Count set bits in an integer	Link	Link
Find the two non-repeating elements in an array of repeating elements	Link	Link
Count number of bits to be flipped to convert A to B	Link	Link
Count total set bits in all numbers from 1 to n	Link	Link
Program to find whether a no is power of two	Link	Link
Find position of the only set bit	Link	Link
Copy set bits in a range	Link	Link
Divide two integers without using multiplication, division and mod operator	Link	Link
Calculate square of a number without using *, / and pow()	Link	Link
Power Set	Link	Link

Greedy

Question	Article	Practice
Activity Selection Problem	Link	Link
Job Sequencing Problem	Link	Link
Huffman Coding	Link	Link
Water Connection Problem	Link	Link
Fractional Knapsack Problem	Link	Link
Greedy Algorithm to find Minimum number of Coins	Link	Link
Maximum trains for which stoppage can be provided	Link	Link
Minimum Platforms Problem	Link	Link
Buy Maximum Stocks if i stocks can be bought on i-th day	Link	Link
Find the minimum and maximum amount to buy all N candies	Link	Link
Minimize Cash Flow among a given set of friends who have borrowed money from each other	Link	Link
Minimum Cost to cut a board into squares	Link	Link
Check if it is possible to survive on Island	Link	Link
Find maximum meetings in one room	Link	Link
Maximum product subset of an array	Link	Link
Maximize array sum after K negations	Link	Link
Maximize the sum of arr[i]*i	Link	Link
Maximum sum of absolute difference of an array	Link	Link
Maximize sum of consecutive differences in a circular array	Link	Link
Minimum sum of absolute difference of pairs of two arrays	Link	Link
Program for Shortest Job First (or SJF) CPU Scheduling	Link	Link
Program for Least Recently Used (LRU) Page Replacement algorithm	Link	Link
Smallest subset with sum greater than all other elements	Link	Link
Chocolate Distribution Problem	Link	Link
DEFKIN -Defense of a Kingdom	Link	Link
DIEHARD -DIE HARD	Link	Link
GERGOVIA -Wine trading in Gergovia	Link	Link
Picking Up Chicks	Link	Link
CHOCOLA –Chocolate	Link	Link
ARRANGE -Arranging Amplifiers	Link	Link
K Centers Problem	Link	Link
Minimum Cost of ropes	Link	Link
Find smallest number with given number of digits and sum of digits	Link	Link
Rearrange characters in a string such that no two adjacent are same	Link	Link
Find maximum sum possible equal sum of three stacks	Link	Link

Backtracking

Question	Article	Practice
Rat in a maze Problem	Link	Link
Printing all solutions in N-Queen	Link	Link
Word Break Problem using Backtracking	Link	Link
Remove Invalid Parentheses	Link	Link
Sudoku Solver	Link	Link
M Coloring Problem	Link	Link
Print all palindromic partitions of a string	Link	Link
Subset Sum Problem	Link	Link
The Knight’s tour problem	Link	Link
Tug of War	Link	Link
Find shortest safe route in a path with landmines	Link	Link
Combinational Sum	Link	Link
Find Maximum number possible by doing at-most K swaps	Link	Link
Print all permutations of a string	Link	Link
Find if there is a path of more than k length from a source	Link	Link
Longest Possible Route in a Matrix with Hurdles	Link	Link
Print all possible paths from top left to bottom right of a mXn matrix	Link	Link
Partition of a set into K subsets with equal sum	Link	Link
Find the K-th Permutation Sequence of first N natural numbers	Link	Link

Dynamic Programming

Question	Article	Practice
Coin Change Problem	Link	Link
Knapsack Problem	Link	Link
Binomial Coefficient Problem	Link	Link
Permutation Coefficient Problem	Link	Link
Program for nth Catalan Number	Link	Link
Matrix Chain Multiplication	Link	Link
Edit Distance	Link	Link
Subset Sum Problem	Link	Link
Friends Pairing Problem	Link	Link
Gold Mine Problem	Link	Link
Assembly Line Scheduling Problem	Link	Link
Painting the Fence problem	Link	Link
Maximize The Cut Segments	Link	Link
Longest Common Subsequence	Link	Link
Longest Repeated Subsequence	Link	Link
Longest Increasing Subsequence	Link	Link
Space Optimized Solution of LCS	Link	Link
LCS (Longest Common Subsequence) of three strings	Link	Link
Maximum Sum Increasing Subsequence	Link	Link
Count all subsequences having product less than K	Link	Link
Longest subsequence such that difference between adjacent is one	Link	Link
Maximum subsequence sum such that no three are consecutive	Link	Link
Egg Dropping Problem	Link	Link
Maximum Length Chain of Pairs	Link	Link
Maximum size square sub-matrix with all 1s	Link	Link
Maximum sum of pairs with specific difference	Link	Link
Min Cost Path Problem	Link	Link
Maximum difference of zeros and ones in binary string	Link	Link
Minimum number of jumps to reach end	Link	Link
Minimum cost to fill given weight in a bag	Link	Link
Minimum removals from array to make max –min <= K	Link	Link
Longest Common Substring	Link	Link
Count number of ways to reach a given score in a game	Link	Link
Count Balanced Binary Trees of Height h	Link	Link
LargestSum Contiguous Subarray [V>V>V>V IMP ]	Link	Link
Smallest sum contiguous subarray	Link	Link
Unbounded Knapsack (Repetition of items allowed)	Link	Link
Word Break Problem	Link	Link
Largest Independent Set Problem	Link	Link
Partition problem	Link	Link
Longest Palindromic Subsequence	Link	Link
Count All Palindromic Subsequence in a given String	Link	Link
Longest Palindromic Substring	Link	Link
Longest alternating subsequence	Link	Link
Weighted Job Scheduling	Link	Link
Coin game winner where every player has three choices	Link	Link
Count Derangements (Permutation such that no element appears in its original position) [ IMPORTANT ]	Link	Link
Maximum profit by buying and selling a share at most twice [ IMP ]	Link	Link
Optimal Strategy for a Game	Link	Link
Optimal Binary Search Tree	Link	Link
Palindrome Partitioning Problem	Link	Link
Word Wrap Problem	Link	Link
Mobile Numeric Keypad Problem [ IMP ]	Link	Link
Boolean Parenthesization Problem	Link	Link
Largest rectangular sub-matrix whose sum is 0	Link	Link
Largest area rectangular sub-matrix with equal number of 1’s and 0’s [ IMP ]	Link	Link
Maximum sum rectangle in a 2D matrix	Link	Link
Maximum profit by buying and selling a share at most k times	Link	Link
Find if a string is interleaved of two other strings	Link	Link
Maximum Length of Pair Chain	Link	Link

Stacks and Queues

Question	Article	Practice
Implement Stack from Scratch	Link	Link
Implement Queue from Scratch	Link	Link
Implement 2 stack in an array	Link	Link
Find the middle element of a stack	Link	Link
Implement “N” stacks in an Array	Link	Link
Check the expression has valid or Balanced parenthesis or not.	Link	Link
Reverse a String using Stack	Link	Link
Design a Stack that supports getMin() in O(1) time and O(1) extra space.	Link	Link
Find the next Greater element	Link	Link
The celebrity Problem	Link	Link
Arithmetic Expression evaluation	Link	Link
Evaluation of Postfix expression	Link	Link
Implement a method to insert an element at its bottom without using any other data structure.	Link	Link
Reverse a stack using recursion	Link	Link
Sort a Stack using recursion	Link	Link
Merge Overlapping Intervals	Link	Link
Largest rectangular Area in Histogram	Link	Link
Length of the Longest Valid Substring	Link	Link
Expression contains redundant bracket or not	Link	Link
Implement Stack using Queue	Link	Link
Implement Stack using Deque	Link	Link
Stack Permutations (Check if an array is stack permutation of other)	Link	Link
Implement Queue using Stack	Link	Link
Implement “n” queue in an array	Link	Link
Implement a Circular queue	Link	Link
LRU Cache Implementation	Link	Link
Reverse a Queue using recursion	Link	Link
Reverse the first “K” elements of a queue	Link	Link
Interleave the first half of the queue with second half	Link	Link
Find the first circular tour that visits all Petrol Pumps	Link	Link
Minimum time required to rot all oranges	Link	Link
Distance of nearest cell having 1 in a binary matrix	Link	Link
First negative integer in every window of size “k”	Link	Link
Check if all levels of two trees are anagrams or not.	Link	Link
Sum of minimum and maximum elements of all subarrays of size “k”.	Link	Link
Minimum sum of squares of character counts in a given string after removing “k” characters.	Link	Link
Queue based approach or first non-repeating character in a stream.	Link	Link
Next Smaller Element	Link	Link

Binary Trees

Question	Article	Practice
Level order traversal	Link	Link
Reverse Level Order traversal	Link	Link
Height of a tree	Link	Link
Diameter of a tree	Link	Link
Mirror of a tree	Link	Link
Inorder Traversal of a tree both using recursion and Iteration	Link	Link
Preorder Traversal of a tree both using recursion and Iteration	Link	Link
Postorder Traversal of a tree both using recursion and Iteration	Link	Link
Left View of a tree	Link	Link
Right View of Tree	Link	Link
Top View of a tree	Link	Link
Bottom View of a tree	Link	Link
Zig-Zag traversal of a binary tree	Link	Link
Check if a tree is balanced or not	Link	Link
Diagonal Traversal of a Binary tree	Link	Link
Boundary traversal of a Binary tree	Link	Link
Construct Binary Tree from String with Bracket Representation	Link	Link
Convert Binary tree into Doubly Linked List	Link	Link
Convert Binary tree into Sum tree	Link	Link
Construct Binary tree from Inorder and preorder traversal	Link	Link
Find minimum swaps required to convert a Binary tree into BST	Link	Link
Check if Binary tree is Sum tree or not	Link	Link
Check if all leaf nodes are at same level or not	Link	Link
Check if a Binary Tree contains duplicate subtrees of size 2 or more [ IMP ]	Link	Link
Check if 2 trees are mirror or not	Link	Link
Sum of Nodes on the Longest path from root to leaf node	Link	Link
Check if given graph is tree or not. [ IMP ]	Link	Link
Find Largest subtree sum in a tree	Link	Link
Maximum Sum of nodes in Binary tree such that no two are adjacent	Link	Link
Print all “K” Sum paths in a Binary tree	Link	Link
Find LCA in a Binary tree	Link	Link
Find distance between 2 nodes in a Binary tree	Link	Link
Kth Ancestor of node in a Binary tree	Link	Link
Find all Duplicate subtrees in a Binary tree [ IMP ]	Link	Link
Tree Isomorphism Problem	Link	Link

Binary Search Tree:

Question	Article	Practice
Find a value in a BST	Link	Link
Deletion of a node in a BST	Link	Link
Find min and max value in a BST	Link	Link
Find inorder successor and inorder predecessor in a BST	Link	Link
Check if a tree is a BST or not	Link	Link
Populate Inorder successor of all nodes	Link	Link
Find LCA of 2 nodes in a BST	Link	Link
Construct BST from preorder traversal	Link	Link
Convert Binary tree into BST	Link	Link
Convert a normal BST into a Balanced BST	Link	Link
Merge two BST [ V.V.V>IMP ]	Link	Link
Find Kth largest element in a BST	Link	Link
Find Kth smallest element in a BST	Link	Link
Count pairs from 2 BST whose sum is equal to given value “X”	Link	Link
Find the median of BST in O(n) time and O(1) space	Link	Link
Count BST nodes that lie in a given range	Link	Link
Replace every element with the least greater element on its right	Link	Link
Given “n” appointments, find the conflicting appointments	Link	Link
Check preorder is valid or not	Link	Link
Check whether BST contains Dead end	Link	Link
Largest BST in a Binary Tree [ V.V.V.V.V IMP ]	Link	Link
Flatten BST to sorted list	Link	Link

Graphs

Question	Article	Practice
Create a Graph, print it	Link	Link
Implement BFS algorithm	Link	Link
Implement DFS Algo	Link	Link
Detect Cycle in Directed Graph using BFS/DFS Algo	Link	Link
Detect Cycle in UnDirected Graph using BFS/DFS Algo	Link	Link
Search in a Maze	Link	Link
Minimum Step by Knight	Link	Link
Flood fill algo	Link	Link
Clone a graph	Link	Link
Making wired Connections	Link	Link
Word Ladder	Link	Link
Dijkstra algo	Link	Link
Implement Topological Sort	Link	Link
Minimum time taken by each job to be completed given by a Directed Acyclic Graph	Link	Link
Find whether it is possible to finish all tasks or not from given dependencies	Link	Link
Find the no. of Islands	Link	Link
Given a sorted Dictionary of an Alien Language, find order of characters	Link	Link
Implement Kruksal’sAlgorithm	Link	Link
Implement Prim’s Algorithm	Link	Link
Total no. of Spanning tree in a graph	Link	Link
Implement Bellman Ford Algorithm	Link	Link
Implement Floyd warshall Algorithm	Link	Link
Travelling Salesman Problem	Link	Link
Graph Colouring Problem	Link	Link
Snake and Ladders Problem	Link	Link
Find bridge in a graph	Link	Link
Count Strongly connected Components(Kosaraju Algo)	Link	Link
Check whether a graph is Bipartite or Not	Link	Link
Detect Negative cycle in a graph	Link	Link
Longest path in a Directed Acyclic Graph	Link	Link
Journey to the Moon	Link	Link
Cheapest Flights Within K Stops	Link	Link
Oliver and the Game	Link	Link
Water Jug problem using BFS	Link	Link
Find if there is a path of more thank length from a source	Link	Link
M-Colouring Problem	Link	Link
Minimum edges to reverse to make path from source to destination	Link	Link
Paths to travel each nodes using each edge(Seven Bridges)	Link	Link
Vertex Cover Problem	Link	Link
Chinese Postman or Route Inspection	Link	Link
Number of Triangles in a Directed and Undirected Graph	Link	Link
Minimise the cashflow among a given set of friends who have borrowed money from each other	Link	Link
Two Clique Problem	Link	Link

Heap

Question	Article	Practice
Implement a Maxheap/MinHeap using arrays and recursion.	Link	Link
Sort an Array using heap. (HeapSort)	Link	Link
Maximum of all subarrays of size k.	Link	Link
“K” largest element in an array	Link	Link
Kth smallest and largest element in an unsorted array	Link	Link
Merge “K” sorted arrays. [ IMP ]	Link	Link
Merge 2 Binary Max Heaps	Link	Link
Kth largest sum continuous subarrays	Link	Link
Leetcode- reorganize strings	Link	Link
Merge “K” Sorted Linked Lists [V.IMP]	Link	Link
Smallest range in “K” Lists	Link	Link
Median in a stream of Integers	Link	Link
Check if a Binary Tree is Heap	Link	Link
Connect “n” ropes with minimum cost	Link	Link
Convert BST to Min Heap	Link	Link
Convert min heap to max heap	Link	Link
Rearrange characters in a string such that no two adjacent are same.	Link	Link
Minimum sum of two numbers formed from digits of an array	Link	Link

Trie

Question	Article	Practice
Construct a trie from scratch	Link	Link
Find shortest unique prefix for every word in a given list	Link	Link
Word Break Problem \| (Trie solution)	Link	Link
Given a sequence of words, print all anagrams together	Link	Link
Implement a Phone Directory	Link	Link
Print unique rows in a given boolean matrix	Link	Link