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 447 Check If Given Undirected Graph is a tree Medium % 0 446 Print all middle elements of the given matrix/2D array. Beginner % 1 445 Depth-First Search (DFS) in 2D Matrix/2D-Array - Recursive Solution Beginner % 1 444 Articulation Points OR Cut Vertices in a Graph Hard % 0 443 Check the completeness of given binary tree | Set 2 - Using Level Order Traversal Medium % 0 442 Find the number of distinct Islands OR connected components. Hard % 0 441 Print All Paths in Dijkstra's Shortest Path Algorithm Hard % 0 440 Given an array, Print sum of all subsets Beginner % 1 439 Determine the given routing number belong to which bank Medium % 0 438 Check if interval is covered in given coordinates Medium % 0 437 Lexicographically previous permutation With One swap Medium % 1 436 Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Medium % 0 435 Hamming Distance between two given integers Beginner % 1 434 Print boundary of given matrix/2D array. Beginner % 1 433 Depth-First Search (DFS) in 2D Matrix/2D-Array - Iterative Solution Beginner % 0 432 Breadth-First Search (BFS) in 2D Matrix/2D-Array Beginner % 1 431 Check the completeness of given binary tree | Set 1 - Using Node Count Medium % 0 430 Longest substring with at most K unique characters Medium % 2 429 Find all the Armstrong numbers in the given range Beginner % 0 428 Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Medium % 0 427 Number of Islands using BFS Medium % 0 426 Check if Graph is Bipartite - Adjacency List using Depth-First Search(DFS) Hard % 0 425 Check if the given binary tree is Full or not Beginner % 1 424 Check if given undirected graph is connected or not Beginner % 0 423 Given Graph - Remove a vertex and all edges connect to the vertex Medium % 0 422 Print Stack in reverse order Beginner % 0 421 Sort a given stack - Using Recursion Hard % 1 420 Number's Complement - 2 Approaches Medium % 1 419 Print all subsets of an array with a sum equal to zero Medium % 0 418 Social Network Problem Hard % 0 417 Maximum number edges to make Acyclic Undirected/Directed Graph Beginner % 0 416 Evaluation of Prefix Expressions (Polish Notation) | Set 2 Medium % 0 415 Hamming Distance between two given strings Beginner % 0 414 Breadth-First Search in Disconnected Graph Medium % 0 413 ZigZag OR Diagonal traversal in 2d array/Matrix using queue Medium % 0 Check If Given Undirected Graph is a tree Print all middle elements of the given matrix/2D array. Depth-First Search (DFS) in 2D Matrix/2D-Array - Recursive Solution Articulation Points OR Cut Vertices in a Graph Check the completeness of given binary tree | Set 2 - Using Level Order Traversal Find the number of distinct Islands OR connected components. Print All Paths in Dijkstra's Shortest Path Algorithm Given an array, Print sum of all subsets Determine the given routing number belong to which bank Check if interval is covered in given coordinates Lexicographically previous permutation With One swap Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Hamming Distance between two given integers Print boundary of given matrix/2D array. Depth-First Search (DFS) in 2D Matrix/2D-Array - Iterative Solution Breadth-First Search (BFS) in 2D Matrix/2D-Array Check the completeness of given binary tree | Set 1 - Using Node Count Longest substring with at most K unique characters Find all the Armstrong numbers in the given range Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Number of Islands using BFS Check if Graph is Bipartite - Adjacency List using Depth-First Search(DFS) Check if the given binary tree is Full or not Check if given undirected graph is connected or not Given Graph - Remove a vertex and all edges connect to the vertex Print Stack in reverse order Sort a given stack - Using Recursion Number's Complement - 2 Approaches Print all subsets of an array with a sum equal to zero Social Network Problem Maximum number edges to make Acyclic Undirected/Directed Graph Evaluation of Prefix Expressions (Polish Notation) | Set 2 Hamming Distance between two given strings Breadth-First Search in Disconnected Graph ZigZag OR Diagonal traversal in 2d array/Matrix using queue 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16