1178. Number of Valid Words for Each Puzzle ¶

Problem

With respect to a given puzzle string, a word is valid if both the following conditions are satisfied:

word contains the first letter of puzzle.
For each letter in word, that letter is in puzzle.
- For example, if the puzzle is "abcdefg", then valid words are "faced", "cabbage", and "baggage", while
- invalid words are "beefed" (does not include 'a') and "based" (includes 's' which is not in the puzzle).

Return an array answer, where answer[i] is the number of words in the given word list words that is valid with respect to the puzzle puzzles[i].

Example 1:

Input: words = ["aaaa","asas","able","ability","actt","actor","access"], puzzles = ["aboveyz","abrodyz","abslute","absoryz","actresz","gaswxyz"]
Output: [1,1,3,2,4,0]
Explanation: 
1 valid word for "aboveyz" : "aaaa" 
1 valid word for "abrodyz" : "aaaa"
3 valid words for "abslute" : "aaaa", "asas", "able"
2 valid words for "absoryz" : "aaaa", "asas"
4 valid words for "actresz" : "aaaa", "asas", "actt", "access"
There are no valid words for "gaswxyz" cause none of the words in the list contains letter 'g'.

Example 2:

Input: words = ["apple","pleas","please"], puzzles = ["aelwxyz","aelpxyz","aelpsxy","saelpxy","xaelpsy"]
Output: [0,1,3,2,0]

Constraints:

1 <= words.length <= 10⁵
4 <= words[i].length <= 50
1 <= puzzles.length <= 10⁴
puzzles[i].length == 7
words[i] and puzzles[i] consist of lowercase English letters.
Each puzzles[i] does not contain repeated characters.