Solution: Letter Combinations of a Phone Number

Let's solve the Letter Combinations of a Phone Number problem using the Subsets pattern.


Given a string containing digits from 2 to 9 inclusive, with the possibility of each digit appearing multiple times, return all possible letter combinations that the number could represent. Return the answer in any order.

The illustration below shows the mapping of digits to letters in a telephone dial pad.

Note: The number 11 on the telephone dial pad does not correspond to any letter, so the input string only contains digits from 22 to 99.

Level up your interview prep. Join Educative to access 70+ hands-on prep courses.