# 916. Word Subsets

https://leetcode.com/problems/word-subsets/

You are given two string arrays words1 and words2. A string b is a subset of string a if every letter in b occurs in a including multiplicity.

``````For example, "wrr" is a subset of "warrior" but is not a subset of "world".A string a from words1 is **universal** if for every string b in words2, b is a subset of a.
``````

Return an array of all the universal strings in words1. You may return the answer in any order.

Constraints:

``````1 <= words1.length, words2.length <= 104
1 <= words1[i].length, words2[i].length <= 10
words1[i] and words2[i] consist only of lowercase English letters.
All the strings of words1 are **unique**.
``````

• code
``````class Solution {
public List<String> wordSubsets(String[] words1, String[] words2) {
int[] count = new int;
for (String word: words2) {
int[] wordcount = new int;
for (char c: word.toCharArray()) {
wordcount[c - 'a']++;
if (wordcount[c - 'a'] > count[c - 'a']) count[c - 'a']++;
}
}
List<String> res = new ArrayList<>();

for (String word: words1) {
int[] cur = new int;
boolean valid = true;
for (char c: word.toCharArray()) {
cur[c - 'a']++;
}
for (int i = 0; i < 26; i++){
if (count[i] > cur[i]) {
valid = false;
break;
}
}