2416. Sum of Prefix Scores of Strings
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You are given an array words of size n consisting of non-empty strings.
We define the score of a string term as the number of strings words[i] such that term is a prefix of words[i].
- For example, if
words = ["a", "ab", "abc", "cab"], then the score of"ab"is2, since"ab"is a prefix of both"ab"and"abc".
Return an array answer of size n where answer[i] is the sum of scores of every non-empty prefix of words[i].
Note that a string is considered as a prefix of itself.
Example 1:
Input: words = ["abc","ab","bc","b"] Output: [5,4,3,2] Explanation: The answer for each string is the following: - "abc" has 3 prefixes: "a", "ab", and "abc". - There are 2 strings with the prefix "a", 2 strings with the prefix "ab", and 1 string with the prefix "abc". The total is answer[0] = 2 + 2 + 1 = 5. - "ab" has 2 prefixes: "a" and "ab". - There are 2 strings with the prefix "a", and 2 strings with the prefix "ab". The total is answer[1] = 2 + 2 = 4. - "bc" has 2 prefixes: "b" and "bc". - There are 2 strings with the prefix "b", and 1 string with the prefix "bc". The total is answer[2] = 2 + 1 = 3. - "b" has 1 prefix: "b". - There are 2 strings with the prefix "b". The total is answer[3] = 2.
Example 2:
Input: words = ["abcd"] Output: [4] Explanation: "abcd" has 4 prefixes: "a", "ab", "abc", and "abcd". Each prefix has a score of one, so the total is answer[0] = 1 + 1 + 1 + 1 = 4.
Constraints:
1 <= words.length <= 10001 <= words[i].length <= 1000words[i]consists of lowercase English letters.
Hints
Hint 1
What data structure will allow you to efficiently keep track of the score of each prefix?
Hint 2
Use a Trie. Insert all the words into it, and keep a counter at each node that will tell you how many times we have visited each prefix.