Question

Suppose you have a dictionary that contains valid words.

Given an input string with all spaces removed, determine whether the string is composed of valid words or not.

You can assume the dictionary is a hashtable that provides O(1) lookup.

Please give a recurrence relation for this. I found this question in a book , but the book gives no answer?

Answer 1

IsWordValid(S) = for word in dict:
                    if S.startsWith(word) and IsWordValid(S[word.length:])
                          return true
                 return false
IsWordValid(null) = true