Problem Statement | |||||||||||||
| A prefix code is a set of words in which no word is a prefix of another word in the set.
A word v is said to be a prefix of a word w if w starts with v. An important property of prefix codes is that they are uniquely decodable. Prefix codes are commonly used - telephone numbers are an everyday example (as you probably don't want a stranger to pick up the phone call you make just because his number is a prefix of the number you intend to dial). Prefix codes are also very popular in computer science, the Huffman code used for data compression being a famous example. Given a String[] words, return the String "Yes" if that set of words is a prefix code or return the String "No, i" if it is not, where i is replaced by the lowest 0-based index of a String in words that is a prefix of another String in words. (That index should have no extra leading zeros.) | |||||||||||||
Definition | |||||||||||||
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Notes | |||||||||||||
| - | Letters are case sensitive (e.g. "No" is not a prefix of "not"). | ||||||||||||
| - | Do not forget the single space between the comma and i in "No, i" | ||||||||||||
Constraints | |||||||||||||
| - | words contains between 1 and 50 elements, inclusive. | ||||||||||||
| - | Each element of words contains between 1 and 50 characters, inclusive. | ||||||||||||
| - | Each element of words consists only of characters '0'-'9', 'A'-'Z' and 'a'-'z', inclusive. | ||||||||||||
| - | No two elements of words are equal (as the input represents a set). | ||||||||||||
Examples | |||||||||||||
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