# Status Problem Level Completes Likes 1 Counting the Largest Number Groups by Digit Sum Medium % 2 2 Adding One to a Number Represented by an Array Medium % 1 3 Find the Nth-term in a given arithmetic progression Beginner % 0 4 Convert a Decimal number to its binary representation Beginner % 1 5 In a number, add digits until it becomes a single digit Beginner % 1 6 Add digits until the number becomes a single digit Beginner % 0 7 Calculate tax on income as per given tax brackets. Beginner % 0 8 Valid Pickup and Delivery options Hard % 0 9 The largest number can be formed from the given number Beginner % 0 10 Construct the Largest number from the given digits Beginner % 1 11 Numbers with prime set bits in a given range using Sieve of Eratosthenes Algorithm Medium % 0 12 Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Medium % 0 13 Hamming Distance between two given integers Beginner % 1 14 Find all the Armstrong numbers in the given range Beginner % 0 15 Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Medium % 0 16 Check if Number is divisible by its digits Beginner % 0 17 Check if the given number is Armstrong number or not Beginner % 0 18 Evaluation of Prefix Expressions (Polish Notation) | Set 1 Medium % 0 19 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 2 Medium % 0 20 Evaluation of Postfix Expressions (Polish Postfix notation) | Set 1 Medium % 0 21 Find all the numbers in the range which has prime set bits. Beginner % 0 22 Smallest Number after Removing K digits Hard % 0 23 Find the maximum number present in a String Beginner % 0 24 Convert Prefix to Postfix Expression Medium % 0 25 Convert Roman Number to Integer Beginner % 0 26 Convert Postfix to Prefix Expression Medium % 0 27 Convert Integer to Roman Medium % 0 28 String to Integer (AtoI - ASCII to Integer) - Recursive Solution Medium % 0 29 Sieve of Eratosthenes - Find all Prime Numbers less than equal to N | Set 2 Medium % 0 30 Convert Postfix to Infix Expression Medium % 0 31 Collatz Conjecture - Steps to transform Number to 1 Beginner % 0 32 String to Integer (AtoI - ASCII to Integer) Beginner % 1 33 Find all Prime Numbers less than equal to N | Set 1 Beginner % 0 34 Monotone Increasing Digits Medium % 1 35 Convert Infix to Prefix Expression Medium % 0 Counting the Largest Number Groups by Digit Sum Adding One to a Number Represented by an Array Find the Nth-term in a given arithmetic progression Convert a Decimal number to its binary representation In a number, add digits until it becomes a single digit Add digits until the number becomes a single digit Calculate tax on income as per given tax brackets. Valid Pickup and Delivery options The largest number can be formed from the given number Construct the Largest number from the given digits Numbers with prime set bits in a given range using Sieve of Eratosthenes Algorithm Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N Hamming Distance between two given integers Find all the Armstrong numbers in the given range Collatz Conjecture - Maximum Steps takes to transform (1, N) to 1. Check if Number is divisible by its digits Check if the given number is Armstrong number or not 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. Smallest Number after Removing K digits Find the maximum number present in a String Convert Prefix to Postfix Expression Convert Roman Number to Integer Convert Postfix to Prefix Expression Convert Integer to Roman String to Integer (AtoI - ASCII to Integer) - Recursive Solution Sieve of Eratosthenes - Find all Prime Numbers less than equal to N | Set 2 Convert Postfix to Infix Expression Collatz Conjecture - Steps to transform Number to 1 String to Integer (AtoI - ASCII to Integer) Find all Prime Numbers less than equal to N | Set 1 Monotone Increasing Digits Convert Infix to Prefix Expression 1 2