longest-word-in-dictionary

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720. Longest Word in Dictionary (Easy)

Given an array of strings words representing an English Dictionary, return the longest word in words that can be built one character at a time by other words in words.

If there is more than one possible answer, return the longest word with the smallest lexicographical order. If there is no answer, return the empty string.

 

Example 1:

Input: words = ["w","wo","wor","worl","world"]
Output: "world"
Explanation: The word "world" can be built one character at a time by "w", "wo", "wor", and "worl".

Example 2:

Input: words = ["a","banana","app","appl","ap","apply","apple"]
Output: "apple"
Explanation: Both "apply" and "apple" can be built from other words in the dictionary. However, "apple" is lexicographically smaller than "apply".

 

Constraints:

• 1 <= words.length <= 1000
• 1 <= words[i].length <= 30
• words[i] consists of lowercase English letters.

Related Topics

[Trie] [Array] [Hash Table] [String] [Sorting]

Similar Questions

1. Longest Word in Dictionary through Deleting (Medium)
2. Implement Magic Dictionary (Medium)

Hints

Hint 1

For every word in the input list, we can check whether all prefixes of that word are in the input list by using a Set.