Question

916. Word Subsets

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Description

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.

 

Example 1:

Input: words1 = ["amazon","apple","facebook","google","leetcode"], words2 = ["e","o"]
Output: ["facebook","google","leetcode"]

Example 2:

Input: words1 = ["amazon","apple","facebook","google","leetcode"], words2 = ["l","e"]
Output: ["apple","google","leetcode"]

 

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.

Solutions

Solution 1

class Solution:
  def wordSubsets(self, words1: List[str], words2: List[str]) -> List[str]:
    cnt = Counter()
    for b in words2:
      t = Counter(b)
      for c, v in t.items():
        cnt[c] = max(cnt[c], v)
    ans = []
    for a in words1:
      t = Counter(a)
      if all(v <= t[c] for c, v in cnt.items()):
        ans.append(a)
    return ans

class Solution {
  public List<String> wordSubsets(String[] words1, String[] words2) {
    int[] cnt = new int[26];
    for (var b : words2) {
      int[] t = new int[26];
      for (int i = 0; i < b.length(); ++i) {
        t[b.charAt(i) - 'a']++;
      }
      for (int i = 0; i < 26; ++i) {
        cnt[i] = Math.max(cnt[i], t[i]);
      }
    }
    List<String> ans = new ArrayList<>();
    for (var a : words1) {
      int[] t = new int[26];
      for (int i = 0; i < a.length(); ++i) {
        t[a.charAt(i) - 'a']++;
      }
      boolean ok = true;
      for (int i = 0; i < 26; ++i) {
        if (cnt[i] > t[i]) {
          ok = false;
          break;
        }
      }
      if (ok) {
        ans.add(a);
      }
    }
    return ans;
  }
}

class Solution {
public:
  vector<string> wordSubsets(vector<string>& words1, vector<string>& words2) {
    int cnt[26] = {0};
    int t[26];
    for (auto& b : words2) {
      memset(t, 0, sizeof t);
      for (auto& c : b) {
        t[c - 'a']++;
      }
      for (int i = 0; i < 26; ++i) {
        cnt[i] = max(cnt[i], t[i]);
      }
    }
    vector<string> ans;
    for (auto& a : words1) {
      memset(t, 0, sizeof t);
      for (auto& c : a) {
        t[c - 'a']++;
      }
      bool ok = true;
      for (int i = 0; i < 26; ++i) {
        if (cnt[i] > t[i]) {
          ok = false;
          break;
        }
      }
      if (ok) {
        ans.emplace_back(a);
      }
    }
    return ans;
  }
};

func wordSubsets(words1 []string, words2 []string) (ans []string) {
  cnt := [26]int{}
  for _, b := range words2 {
    t := [26]int{}
    for _, c := range b {
      t[c-'a']++
    }
    for i := range cnt {
      cnt[i] = max(cnt[i], t[i])
    }
  }
  for _, a := range words1 {
    t := [26]int{}
    for _, c := range a {
      t[c-'a']++
    }
    ok := true
    for i, v := range cnt {
      if v > t[i] {
        ok = false
        break
      }
    }
    if ok {
      ans = append(ans, a)
    }
  }
  return
}