Featured Lists Top 20 Problems on Dynamic programming Top 10 Problems on Backtracking Top 20 Problems on Graph Top 25 Problems on Trees Top 10 Problems on Bits Manipulation Top 15 Problems in LinkedList All Problems # Status Problem video Level Completes Likes 214 Find the last non repeating character in a given string. Beginner % 0 213 Find the last repeating character in a given string Beginner % 0 210 k-Nearest Neighbors Hard % 0 206 Reverse the given Array without using built in function Beginner % 0 201 Dynamic Programming - Split the String into Minimum number of Palindromes. Hard % 0 197 Convert Binary Tree into Threaded Binary Tree Hard % 0 196 Double Threaded Binary Tree Complete Implementation Hard % 0 195 Single Threaded Binary Tree Complete Implementation Hard % 0 194 Introduction to Threaded Binary Tree Medium % 0 193 Implement Stack Using Linked List Beginner % 0 192 Doubly Linked List Complete Implementation Beginner % 0 191 Circular Linked List Complete Implementation Beginner % 0 185 Generate Maximum revenue by selling K tickets from N windows Medium % 0 167 Generate Well Ordered Passwords of a Given Length K Medium % 0 166 All N Length Strings from Given String of Length K Medium % 0 155 Find the Kth Smallest/Largest Element in an Array Using Heap Beginner % 0 154 Priority Queue in Data Structure Beginner % 0 150 Sort Names by their Last Names Beginner % 0 142 Locate the Farthest Left Node on the Bottom Level Medium % 0 140 Rearrange Array Elements (A[i] = i) | In-place Approach Medium % 0 138 Find the Maximum Value in a Binary Tree Beginner % 0 133 Reverse Level Order Traversal of Binary Trees Medium % 0 131 Find the Height of a tree without using Recursion Medium % 0 129 Binary Min-Max Heap Implementation Hard % 0 128 Magic Index - Find Index In Sorted Array Such That A[i] = i Beginner % 0 127 Numbers Palindrome in Both Decimal and Octal Beginner % 0 126 Generate All Permutations of a String (Well-Ordered) Medium % 0 125 Find the Increasing Triplet Sub-sequence in an array Medium % 0 124 Create a Specific Triangle Pattern from an Array Beginner % 0 122 Goldbach's Conjecture Beginner % 0 120 Convert Decimal to Irreducible Fraction (Simplified Form) Beginner % 0 117 Stack with Max Tracking: Find the Largest Element (Optimized) Medium % 1 114 Counting Sort Algorithm Medium % 0 113 Towers Of Hanoi Beginner % 0 110 Tricky Sorting: Sort 3 Numbers Without If Statements (or Only Max()) Beginner % 0 Find the last non repeating character in a given string. Find the last repeating character in a given string k-Nearest Neighbors Reverse the given Array without using built in function Dynamic Programming - Split the String into Minimum number of Palindromes. Convert Binary Tree into Threaded Binary Tree Double Threaded Binary Tree Complete Implementation Single Threaded Binary Tree Complete Implementation Introduction to Threaded Binary Tree Implement Stack Using Linked List Doubly Linked List Complete Implementation Circular Linked List Complete Implementation Generate Maximum revenue by selling K tickets from N windows Generate Well Ordered Passwords of a Given Length K All N Length Strings from Given String of Length K Find the Kth Smallest/Largest Element in an Array Using Heap Priority Queue in Data Structure Sort Names by their Last Names Locate the Farthest Left Node on the Bottom Level Rearrange Array Elements (A[i] = i) | In-place Approach Find the Maximum Value in a Binary Tree Reverse Level Order Traversal of Binary Trees Find the Height of a tree without using Recursion Binary Min-Max Heap Implementation Magic Index - Find Index In Sorted Array Such That A[i] = i Numbers Palindrome in Both Decimal and Octal Generate All Permutations of a String (Well-Ordered) Find the Increasing Triplet Sub-sequence in an array Create a Specific Triangle Pattern from an Array Goldbach's Conjecture Convert Decimal to Irreducible Fraction (Simplified Form) Stack with Max Tracking: Find the Largest Element (Optimized) Counting Sort Algorithm Towers Of Hanoi Tricky Sorting: Sort 3 Numbers Without If Statements (or Only Max()) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16