# Status Problem video Level Completes Likes 527 In a number, add digits until it becomes a single digit Beginner % 1 495 Print all nested directories and files in a given directory - Recursion Medium % 0 484 Print all subarrays using recursion Medium % 1 468 Unique subsets with a given sum with allowed repeated digits. Medium % 0 467 Print all steps to convert one string to another string Medium % 0 465 Find all subsets of size K from a given number N (1 to N) Medium % 0 463 Combinations with sum K from a given number N with repetition Medium % 0 457 Given an array, print all unique subsets with a given sum. Medium % 0 454 Find all unique combinations of numbers (from 1 to 9 ) with sum to N Medium % 0 445 Depth-First Search (DFS) in 2D Matrix/2D-Array - Recursive Solution Beginner % 1 442 Find the number of distinct Islands OR connected components. Hard % 0 440 Given an array, Print sum of all subsets Beginner % 1 436 Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Medium % 0 428 Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Medium % 0 427 Number of Islands using BFS Medium % 0 422 Print Stack in reverse order Beginner % 0 419 Print all subsets of an array with a sum equal to zero Medium % 0 408 Number of Islands Medium % 1 407 Integer Replacement Problem Medium % 0 399 Round Price Problem Hard % 0 In a number, add digits until it becomes a single digit Print all nested directories and files in a given directory - Recursion Print all subarrays using recursion Unique subsets with a given sum with allowed repeated digits. Print all steps to convert one string to another string Find all subsets of size K from a given number N (1 to N) Combinations with sum K from a given number N with repetition Given an array, print all unique subsets with a given sum. Find all unique combinations of numbers (from 1 to 9 ) with sum to N Depth-First Search (DFS) in 2D Matrix/2D-Array - Recursive Solution Find the number of distinct Islands OR connected components. Given an array, Print sum of all subsets Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Number of Islands using BFS Print Stack in reverse order Print all subsets of an array with a sum equal to zero Number of Islands Integer Replacement Problem Round Price Problem 1 2 3 4 5 6 7 8