Description
Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order. Mapping: 2-abc, 3-def, 4-ghi, 5-jkl, 6-mno, 7-pqrs, 8-tuv, 9-wxyz.
Examples
Input:
digits = "23"Output:
["ad","ae","af","bd","be","bf","cd","ce","cf"]Explanation:
All combinations of letters for digits 2 and 3.
Input:
digits = ""Output:
[]Explanation:
Empty input returns empty array.
Input:
digits = "2"Output:
["a","b","c"]Explanation:
Letters mapped to digit 2.
Constraints
- •
0 ≤ digits.length ≤ 4 - •
digits[i] is a digit in the range ['2', '9'].