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 380 Count the number of nodes in a given binary tree Beginner % 0 378 Longest contiguous character in a given String - O(N) Solution Beginner % 0 377 Convert Postfix to Infix Expression Medium % 0 373 Longest substring with at most two unique characters Medium % 0 371 Convert Infix to Prefix Expression Medium % 0 368 Max Flow Problem - Ford-Fulkerson Algorithm Hard % 0 367 Sum of all Unique elements in a given array Beginner % 0 365 Convert Infix to Postfix Expression Medium % 0 364 Find three smallest elements in a given array Beginner % 0 363 Evaluation of Infix expressions Medium % 0 362 Stack Java Class - Explained Beginner % 0 359 Merge K sorted Linked List - Using Priority Queue Hard % 0 358 Infix, Postfix and Prefix Notations/Expressions Beginner % 0 353 Reverse a given number Beginner % 1 351 Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List | Set 1 Hard % 1 350 Find first three largest elements in a given array Beginner % 0 347 Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Hard % 0 344 Given two strings validate the output string Beginner % 0 339 Multiply with power of 2 without using pow() or * operator Beginner % 1 338 Find Number of reverse pairs in an array Hard % 1 334 Dijkstra Algorithm Implementation – TreeSet Hard % 0 330 Check if Given Number is power of 2 Beginner % 1 318 Calculate Log2n without using built-in function Beginner % 1 313 Check if two Strings are equal without using built-in function Beginner % 0 312 Remove Vowels from a given String Beginner % 0 305 Find number of Distinct Permutations of a String Medium % 0 301 Bitwise Trick: Divide by Powers of 2 Without Operators Beginner % 1 293 Convert Number to base 3 String Representation Beginner % 1 290 Reverse a String using Recursion Beginner % 0 277 Graph – Count all paths between source and destination Medium % 1 273 Graph – Detect Cycle in a Directed Graph Medium % 1 272 Graph – Software Installation Problem Medium % 0 269 Graph – Depth First Search in Disconnected Graph Medium % 1 266 Graph Implementation – Adjacency Matrix | Set 3 Beginner % 1 262 Count and print all Subarrays with product less than K in O(n) Hard % 0 Count the number of nodes in a given binary tree Longest contiguous character in a given String - O(N) Solution Convert Postfix to Infix Expression Longest substring with at most two unique characters Convert Infix to Prefix Expression Max Flow Problem - Ford-Fulkerson Algorithm Sum of all Unique elements in a given array Convert Infix to Postfix Expression Find three smallest elements in a given array Evaluation of Infix expressions Stack Java Class - Explained Merge K sorted Linked List - Using Priority Queue Infix, Postfix and Prefix Notations/Expressions Reverse a given number Least Recently Used (LRU) Cache – Using HashMap and Doubly Linked List | Set 1 Find first three largest elements in a given array Find the nearest building which has bike | Find nearest specific vertex from source in a graph. Given two strings validate the output string Multiply with power of 2 without using pow() or * operator Find Number of reverse pairs in an array Dijkstra Algorithm Implementation – TreeSet Check if Given Number is power of 2 Calculate Log2n without using built-in function Check if two Strings are equal without using built-in function Remove Vowels from a given String Find number of Distinct Permutations of a String Bitwise Trick: Divide by Powers of 2 Without Operators Convert Number to base 3 String Representation Reverse a String using Recursion Graph – Count all paths between source and destination Graph – Detect Cycle in a Directed Graph Graph – Software Installation Problem Graph – Depth First Search in Disconnected Graph Graph Implementation – Adjacency Matrix | Set 3 Count and print all Subarrays with product less than K in O(n) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
