Lua Coding Practice

Solve Phone Number Letter Combinations using Lua Language

Solve Phone Number Letter Combinations using Lua to enhance your skills with lua coding practice , master coding concepts, and prepare for interviews with practical exercises and detailed solutions.

Phone Number Letter Combinations

Difficulty : Easy

Categories :

  • Backtracking

Given a string containing digits from 2-9, return all possible letter combinations that the number could represent on a phone keypad. Similar to old phone keypads where:

  • 2 = abc
  • 3 = def
  • 4 = ghi
  • 5 = jkl
  • 6 = mno
  • 7 = pqrs
  • 8 = tuv
  • 9 = wxyz

Constraints:

  • 0 ≤ digits.length ≤ 4
  • digits[i] is a digit in the range ['2', '9']
  • Return combinations in any order

Examples:

Input: "23"
Output: ["ad","ae","af","bd","be","bf","cd","ce","cf"]
Explanation: All possible combinations of '2' (abc) and '3' (def)
Input: "2"
Output: ["a","b","c"]
Explanation: All possible letters for '2'

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