Formatted question description: https://leetcode.ca/all/916.html

# 916. Word Subsets (Medium)

We are given two arrays A and B of words.  Each word is a string of lowercase letters.

Now, say that word b is a subset of word 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".

Now say a word a from A is universal if for every b in B, b is a subset of a

Return a list of all universal words in A.  You can return the words in any order.

Example 1:

Input: A = ["amazon","apple","facebook","google","leetcode"], B = ["e","o"]


Example 2:

Input: A = ["amazon","apple","facebook","google","leetcode"], B = ["l","e"]


Example 3:

Input: A = ["amazon","apple","facebook","google","leetcode"], B = ["e","oo"]


Example 4:

Input: A = ["amazon","apple","facebook","google","leetcode"], B = ["lo","eo"]


Example 5:

Input: A = ["amazon","apple","facebook","google","leetcode"], B = ["ec","oc","ceo"]


Note:

1. 1 <= A.length, B.length <= 10000
2. 1 <= A[i].length, B[i].length <= 10
3. A[i] and B[i] consist only of lowercase letters.
4. All words in A[i] are unique: there isn't i != j with A[i] == A[j].

Related Topics:
String

## Solution 1.

// OJ: https://leetcode.com/problems/word-subsets/
// Time: O((A + B) * N) where N is the maximum length of string
// Space: O(1)
class Solution {
public:
vector<string> wordSubsets(vector<string>& A, vector<string>& B) {
int N = A.size(), target = {}, j = 0;
for (auto &b : B) {
int cnt = {};
for (char c : b) cnt[c - 'a']++;
for (int i = 0; i < 26; ++i) target[i] = max(target[i], cnt[i]);
}
for (int i = 0; i < N; ++i) {
int cnt = {};
for (char c : A[i]) cnt[c - 'a']++;
bool valid = true;
for (int k = 0; k < 26 && valid; ++k) valid = target[k] <= cnt[k];
if (valid) A[j++] = A[i];
}
A.resize(j);
return A;
}
};


Java

• class Solution {
public List<String> wordSubsets(String[] A, String[] B) {
List<String> universalList = new ArrayList<String>();
int[] counts = getMaxCounts(B);
for (String word : A) {
int[] wordCounts = getWordCounts(word);
boolean flag = true;
for (int i = 0; i < 26; i++) {
if (wordCounts[i] < counts[i]) {
flag = false;
break;
}
}
if (flag)
}
return universalList;
}

public int[] getMaxCounts(String[] array) {
int[] counts = new int;
for (String word : array) {
int[] curCounts = new int;
char[] wordArray = word.toCharArray();
for (char c : wordArray)
curCounts[c - 'a']++;
for (int i = 0; i < 26; i++)
counts[i] = Math.max(counts[i], curCounts[i]);
}
return counts;
}

public int[] getWordCounts(String word) {
int[] wordCounts = new int;
char[] wordArray = word.toCharArray();
for (char c : wordArray)
wordCounts[c - 'a']++;
return wordCounts;
}
}

• // OJ: https://leetcode.com/problems/word-subsets/
// Time: O((A + B) * N) where N is the maximum length of string
// Space: O(1)
class Solution {
public:
vector<string> wordSubsets(vector<string>& A, vector<string>& B) {
int N = A.size(), target = {}, j = 0;
for (auto &b : B) {
int cnt = {};
for (char c : b) cnt[c - 'a']++;
for (int i = 0; i < 26; ++i) target[i] = max(target[i], cnt[i]);
}
for (int i = 0; i < N; ++i) {
int cnt = {};
for (char c : A[i]) cnt[c - 'a']++;
bool valid = true;
for (int k = 0; k < 26 && valid; ++k) valid = target[k] <= cnt[k];
if (valid) A[j++] = A[i];
}
A.resize(j);
return A;
}
};

• class Solution(object):
def wordSubsets(self, A, B):
"""
:type A: List[str]
:type B: List[str]
:rtype: List[str]
"""
B = set(B)
res = []
count = collections.defaultdict(int)
for b in B:
cb = collections.Counter(b)
for c, v in cb.items():
count[c] = max(count[c], v)
res = []
for a in A:
ca = collections.Counter(a)
isSuccess = True
for c, v in count.items():
if v > ca[c]:
isSuccess = False
break
if isSuccess:
res.append(a)
return res