T9 Keypad Word Generation | Dataford Interview Questions

Given a series of keypresses on your phone, can you write a piece of code that brings up all the possible words that would have had these numbers if they were written with T9 (e.g., 2 is abc, 3 is def, 4 is ghi)?

Implement def letter_combinations(digits):. The input is a string containing digits from 2 through 9; return a list of all possible letter strings in T9 mapping order. Return an empty list for an empty input.

Constraints

0 <= len(digits) <= 8
Every character in digits is one of "2", "3", "4", "5", "6", "7", "8", or "9"
Return combinations in the order induced by the mapping strings
Digits 7 and 9 map to four letters; all other valid digits map to three letters

Function Signature

def letter_combinations(digits):

Your question is T9 Keypad Word Generation. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Constraints

0 <= len(digits) <= 8
Every character in digits is one of "2", "3", "4", "5", "6", "7", "8", or "9"
Return combinations in the order induced by the mapping strings
Digits 7 and 9 map to four letters; all other valid digits map to three letters

Function Signature

def letter_combinations(digits):

Your question is T9 Keypad Word Generation. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.