# Status Problem video Level Completes Likes 466 Lexicographically next permutation With One swap Medium % 1 442 Find the number of distinct Islands OR connected components. Hard % 0 426 Check if Graph is Bipartite - Adjacency List using Depth-First Search(DFS) Hard % 0 416 Evaluation of Prefix Expressions (Polish Notation) | Set 2 Medium % 0 410 Evaluation of Prefix Expressions (Polish Notation) | Set 1 Medium % 0 392 Reverse a Stack using recursion - In Place (Without using extra memory) Hard % 1 390 Convert Prefix to Postfix Expression Medium % 0 388 Sort a given stack - Using Temporary Stack Medium % 0 387 Convert Postfix to Prefix Expression Medium % 0 377 Convert Postfix to Infix Expression Medium % 0 372 Monotone Increasing Digits - Leetcode Medium % 1 371 Convert Infix to Prefix Expression Medium % 0 368 Max Flow Problem - Ford-Fulkerson Algorithm Hard % 0 365 Convert Infix to Postfix Expression Medium % 0 363 Evaluation of Infix expressions Medium % 0 361 Convert Prefix to Infix Expression Medium % 0 359 Merge K sorted Linked List - Using Priority Queue Hard % 0 346 Valid Brackets – Part 2 | Stack Method Beginner % 0 280 Graph – Find Cycle in Undirected Graph using Disjoint Set (Union-Find) Hard % 0 275 Graph – Detect Cycle in a Directed Graph using colors Hard % 0 274 Graph – Detect Cycle in an Undirected Graph using DFS Medium % 0 273 Graph – Detect Cycle in a Directed Graph Medium % 1 256 Print all sub sequences of a given array Hard % 0 251 Dynamic Programming - Egg Dropping Problem Hard % 0 250 Nuts & Bolts Problem (Lock & Key problem) Beginner % 0 223 Stock Single Sell Problem - Dynamic Programming - O(n) Medium % 2 216 Find the element which appears maximum number of times in the array Medium % 0 215 Find duplicates in an given array in O(n) time and O(1) space Medium % 0 214 Find the last non repeating character in a given string. Beginner % 0 213 Find the last repeating character in a given string Beginner % 0 209 Find longest Snake sequence in a given matrix Medium % 1 198 Kadane's Algorithm - Maximum Subarray Problem Medium % 1 195 Single Threaded Binary Tree Complete Implementation Hard % 0 174 Dynamic Programming - Maximum Product Cutting Problem Medium % 1 171 Dynamic Programming - Longest Common Subsequence Medium % 0 Lexicographically next permutation With One swap Find the number of distinct Islands OR connected components. Check if Graph is Bipartite - Adjacency List using Depth-First Search(DFS) Evaluation of Prefix Expressions (Polish Notation) | Set 2 Evaluation of Prefix Expressions (Polish Notation) | Set 1 Reverse a Stack using recursion - In Place (Without using extra memory) Convert Prefix to Postfix Expression Sort a given stack - Using Temporary Stack Convert Postfix to Prefix Expression Convert Postfix to Infix Expression Monotone Increasing Digits - Leetcode Convert Infix to Prefix Expression Max Flow Problem - Ford-Fulkerson Algorithm Convert Infix to Postfix Expression Evaluation of Infix expressions Convert Prefix to Infix Expression Merge K sorted Linked List - Using Priority Queue Valid Brackets – Part 2 | Stack Method Graph – Find Cycle in Undirected Graph using Disjoint Set (Union-Find) Graph – Detect Cycle in a Directed Graph using colors Graph – Detect Cycle in an Undirected Graph using DFS Graph – Detect Cycle in a Directed Graph Print all sub sequences of a given array Dynamic Programming - Egg Dropping Problem Nuts & Bolts Problem (Lock & Key problem) Stock Single Sell Problem - Dynamic Programming - O(n) Find the element which appears maximum number of times in the array Find duplicates in an given array in O(n) time and O(1) space Find the last non repeating character in a given string. Find the last repeating character in a given string Find longest Snake sequence in a given matrix Kadane's Algorithm - Maximum Subarray Problem Single Threaded Binary Tree Complete Implementation Dynamic Programming - Maximum Product Cutting Problem Dynamic Programming - Longest Common Subsequence 1 2