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3093. Longest Common Suffix Queries 👍

  • Time: $O(\Sigma |\texttt{wordsContainer[i]}| + \Sigma |\texttt{wordsQuery[i]}|)$
  • Space: $O(\Sigma |\texttt{wordsContainer[i]}| + |\texttt{wordsQuery}|)$
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struct TrieNode {
  vector<shared_ptr<TrieNode>> children;
  TrieNode() : children(26) {}
  int length = INT_MAX;
  int index = -1;
};

class Solution {
 public:
  vector<int> stringIndices(vector<string>& wordsContainer,
                            vector<string>& wordsQuery) {
    vector<int> ans;
    int minIndex = 0;

    for (int i = 0; i < wordsContainer.size(); ++i) {
      insert(wordsContainer[i], i);
      if (wordsContainer[i].length() < wordsContainer[minIndex].length())
        minIndex = i;
    }

    for (const string& query : wordsQuery) {
      const int index = search(query);
      ans.push_back(index == -1 ? minIndex : index);
    }

    return ans;
  }

 private:
  shared_ptr<TrieNode> root = make_shared<TrieNode>();

  void insert(const string& word, int index) {
    shared_ptr<TrieNode> node = root;
    for (int i = word.length() - 1; i >= 0; --i) {
      const int j = word[i] - 'a';
      if (node->children[j] == nullptr)
        node->children[j] = make_shared<TrieNode>();
      node = node->children[j];
      if (node->length > word.length()) {
        node->length = word.length();
        node->index = index;
      }
    }
  }

  int search(const string& word) {
    shared_ptr<TrieNode> node = root;
    for (int i = word.length() - 1; i >= 0; --i) {
      const int j = word[i] - 'a';
      if (node->children[j] == nullptr)
        return node->index;
      node = node->children[j];
    }
    return node->index;
  }
};

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class TrieNode {
  public TrieNode[] children = new TrieNode[26];
  public boolean isWord = false;
  public int length = Integer.MAX_VALUE;
  public int index = -1;
}

class Solution {
  public int[] stringIndices(String[] wordsContainer, String[] wordsQuery) {
    int[] ans = new int[wordsQuery.length];
    int minIndex = 0;

    for (int i = 0; i < wordsContainer.length; ++i) {
      insert(wordsContainer[i], i);
      if (wordsContainer[i].length() < wordsContainer[minIndex].length())
        minIndex = i;
    }

    for (int i = 0; i < wordsQuery.length; ++i) {
      final int index = search(wordsQuery[i]);
      ans[i] = index == -1 ? minIndex : index;
    }

    return ans;
  }

  private TrieNode root = new TrieNode();

  private void insert(final String word, int index) {
    TrieNode node = root;
    for (int i = word.length() - 1; i >= 0; --i) {
      final int j = word.charAt(i) - 'a';
      if (node.children[j] == null)
        node.children[j] = new TrieNode();
      node = node.children[j];
      if (node.length > word.length()) {
        node.length = word.length();
        node.index = index;
      }
    }
  }

  private int search(final String word) {
    TrieNode node = root;
    for (int i = word.length() - 1; i >= 0; --i) {
      final int j = word.charAt(i) - 'a';
      if (node.children[j] == null)
        return node.index;
      node = node.children[j];
    }
    return node.index;
  }
}

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class TrieNode:
  def __init__(self):
    self.children: dict[str, TrieNode] = {}
    self.isWord = False
    self.length = math.inf
    self.index = -1


class Solution:
  def stringIndices(
      self,
      wordsContainer: list[str],
      wordsQuery: list[str],
  ) -> list[int]:
    ans = []
    root = TrieNode()
    minIndex = min(enumerate(wordsContainer), key=lambda x: len(x[1]))[0]

    def insert(word: str, index: int) -> None:
      node = root
      for c in reversed(word):
        node = node.children.setdefault(c, TrieNode())
        if node.length > len(word):
          node.length = len(word)
          node.index = index

    def search(word: str) -> int:
      node = root
      for c in reversed(word):
        if c not in node.children:
          return node.index
        node = node.children[c]
      return node.index

    for i, word in enumerate(wordsContainer):
      insert(word, i)

    for query in wordsQuery:
      index = search(query)
      ans.append(minIndex if index == -1 else index)

    return ans