# Status Problem video Level Completes Likes 529 Duplicate even elements in an array Beginner % 1 525 Find the number of pairs with odd XOR Beginner % 2 517 Count number of pairs in an array with sum = K Medium % 0 516 Count similar words in a given array Beginner % 0 509 Find the Number of Contiguous Parking Areas Medium % 1 498 The largest number can be formed from the given number Beginner % 0 495 Print all nested directories and files in a given directory - Recursion Medium % 0 493 Maximum meetings in one room Medium % 0 488 Check if given sudoku is valid or not Medium % 0 485 Construct the Largest number from the given digits Beginner % 1 478 Efficient Robot Problem - Find Minimum Trips Hard % 0 473 Given an array, count the number of pairs with a given sum. Beginner % 0 471 Two Sum Problem Beginner % 0 470 Find if any two intervals overlap in given intervals Medium % 0 465 Find all subsets of size K from a given number N (1 to N) Medium % 0 463 Find all possible combinations with sum K from a given number N(1 to N) with the repetition of numbers is allowed Medium % 0 461 Insert a node in the given sorted linked list. Beginner % 1 460 Construct the largest number from the given array. Medium % 0 454 Find all unique combinations of numbers (from 1 to 9 ) with sum to N Medium % 0 452 Activity Selection Problem Medium % 0 451 Find the sum of overlapping elements in two sets Beginner % 0 443 Check the completeness of given binary tree | Set 2 - Using Level Order Traversal Medium % 0 440 Given an array, Print sum of all subsets Beginner % 1 437 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 % 0 431 Check the completeness of given binary tree | Set 1 - Using Node Count Medium % 0 425 Check if the given binary tree is Full or not. Beginner % 1 422 Print Stack in reverse order. Beginner % 0 417 Maximum number edges to make Acyclic Undirected/Directed Graph Beginner % 0 416 Evaluation of Prefix Expressions (Polish Notation) | Set 2 Medium % 0 413 ZigZag OR Diagonal traversal in 2d array/Matrix using queue Medium % 0 410 Evaluation of Prefix Expressions (Polish Notation) | Set 1 Medium % 0 406 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2 Medium % 0 405 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 1 Medium % 0 404 Find all the numbers in the range which has prime set bits. Beginner % 0 Duplicate even elements in an array Find the number of pairs with odd XOR Count number of pairs in an array with sum = K Count similar words in a given array Find the Number of Contiguous Parking Areas The largest number can be formed from the given number Print all nested directories and files in a given directory - Recursion Maximum meetings in one room Check if given sudoku is valid or not Construct the Largest number from the given digits Efficient Robot Problem - Find Minimum Trips Given an array, count the number of pairs with a given sum. Two Sum Problem Find if any two intervals overlap in given intervals Find all subsets of size K from a given number N (1 to N) Find all possible combinations with sum K from a given number N(1 to N) with the repetition of numbers is allowed Insert a node in the given sorted linked list. Construct the largest number from the given array. Find all unique combinations of numbers (from 1 to 9 ) with sum to N Activity Selection Problem Find the sum of overlapping elements in two sets Check the completeness of given binary tree | Set 2 - Using Level Order Traversal Given an array, Print sum of all subsets Lexicographically previous permutation With One swap Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Check the completeness of given binary tree | Set 1 - Using Node Count Check if the given binary tree is Full or not. Print Stack in reverse order. Maximum number edges to make Acyclic Undirected/Directed Graph Evaluation of Prefix Expressions (Polish Notation) | Set 2 ZigZag OR Diagonal traversal in 2d array/Matrix using queue Evaluation of Prefix Expressions (Polish Notation) | Set 1 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 1 Find all the numbers in the range which has prime set bits. 1 2 3 4