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feat: add solutions to lc problem: No.0425
No.0425.Word Squares
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‎solution/0400-0499/0425.Word Squares/README.md

+183
Original file line numberDiff line numberDiff line change
@@ -52,22 +52,205 @@
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<!-- 这里可写通用的实现逻辑 -->
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**方法一：前缀树 + DFS**
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根据已添加单词确定下一个单词的前缀，继续进行搜索。
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比如已经添加了两个单词 $ball$ 和 $area$，要添加下一个单词，我们首先要获取下一个单词的前缀，第一个字母是第一个单词的第三个位置 $l$，第二个字母是第二个单词的第三个位置 $e$，这样就构成了前缀 $le$。然后找出所有前缀为 $le$ 的单词，作为下一个单词。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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class Trie:
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def __init__(self):
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self.children = [None] * 26
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self.v = []
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def insert(self, w, i):
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node = self
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for c in w:
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idx = ord(c) - ord('a')
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if node.children[idx] is None:
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node.children[idx] = Trie()
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node = node.children[idx]
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node.v.append(i)
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def search(self, w):
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node = self
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for c in w:
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idx = ord(c) - ord('a')
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if node.children[idx] is None:
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return []
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node = node.children[idx]
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return node.v
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class Solution:
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def wordSquares(self, words: List[str]) -> List[List[str]]:
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def dfs(t):
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if len(t) == len(words[0]):
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ans.append(t[:])
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return
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idx = len(t)
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pref = [v[idx] for v in t]
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indexes = trie.search(''.join(pref))
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for i in indexes:
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t.append(words[i])
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dfs(t)
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t.pop()
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trie = Trie()
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ans = []
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for i, w in enumerate(words):
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trie.insert(w, i)
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for w in words:
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dfs([w])
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return ans
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class Trie {
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Trie[] children = new Trie[26];
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List<Integer> v = new ArrayList<>();
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void insert(String word, int i) {
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Trie node = this;
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for (char c : word.toCharArray()) {
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c -= 'a';
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if (node.children[c] == null) {
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node.children[c] = new Trie();
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}
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node = node.children[c];
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node.v.add(i);
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}
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}
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List<Integer> search(String pref) {
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Trie node = this;
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for (char c : pref.toCharArray()) {
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c -= 'a';
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if (node.children[c] == null) {
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return Collections.emptyList();
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}
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node = node.children[c];
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}
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return node.v;
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}
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}
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class Solution {
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private Trie trie = new Trie();
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private String[] words;
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private List<List<String>> ans = new ArrayList<>();
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public List<List<String>> wordSquares(String[] words) {
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this.words = words;
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for (int i = 0; i < words.length; ++i) {
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trie.insert(words[i], i);
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}
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List<String> t = new ArrayList<>();
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for (String w : words) {
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t.add(w);
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dfs(t);
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t.remove(t.size() - 1);
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}
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return ans;
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}
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private void dfs(List<String> t) {
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if (t.size() == words[0].length()) {
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ans.add(new ArrayList<>(t));
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return;
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}
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int idx = t.size();
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StringBuilder pref = new StringBuilder();
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for (String x : t) {
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pref.append(x.charAt(idx));
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}
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List<Integer> indexes = trie.search(pref.toString());
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for (int i : indexes) {
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t.add(words[i]);
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dfs(t);
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t.remove(t.size() - 1);
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}
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}
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}
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```
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### **Go**
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```go
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type Trie struct {
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children [26]*Trie
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v []int
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}
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func newTrie() *Trie {
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return &Trie{}
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}
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func (this *Trie) insert(word string, i int) {
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node := this
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for _, c := range word {
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c -= 'a'
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if node.children[c] == nil {
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node.children[c] = newTrie()
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}
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node = node.children[c]
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node.v = append(node.v, i)
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}
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}
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func (this *Trie) search(word string) []int {
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node := this
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for _, c := range word {
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c -= 'a'
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if node.children[c] == nil {
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return []int{}
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}
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node = node.children[c]
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}
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return node.v
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}
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func wordSquares(words []string) [][]string {
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trie := newTrie()
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for i, w := range words {
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trie.insert(w, i)
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}
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ans := [][]string{}
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var dfs func([]string)
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dfs = func(t []string) {
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if len(t) == len(words[0]) {
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cp := make([]string, len(t))
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copy(cp, t)
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ans = append(ans, cp)
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return
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}
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idx := len(t)
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pref := []byte{}
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for _, v := range t {
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pref = append(pref, v[idx])
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}
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indexes := trie.search(string(pref))
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for _, i := range indexes {
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t = append(t, words[i])
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dfs(t)
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t = t[:len(t)-1]
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}
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}
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for _, w := range words {
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dfs([]string{w})
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}
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return ans
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}
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```
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### **...**

‎solution/0400-0499/0425.Word Squares/README_EN.md

+178-1
Original file line numberDiff line numberDiff line change
@@ -49,13 +49,190 @@ The output consists of two word squares. The order of output does not matter (ju
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### **Python3**
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```python
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class Trie:
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def __init__(self):
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self.children = [None] * 26
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self.v = []
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def insert(self, w, i):
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node = self
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for c in w:
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idx = ord(c) - ord('a')
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if node.children[idx] is None:
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node.children[idx] = Trie()
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node = node.children[idx]
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node.v.append(i)
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def search(self, w):
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node = self
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for c in w:
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idx = ord(c) - ord('a')
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if node.children[idx] is None:
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return []
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node = node.children[idx]
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return node.v
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class Solution:
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def wordSquares(self, words: List[str]) -> List[List[str]]:
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def dfs(t):
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if len(t) == len(words[0]):
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ans.append(t[:])
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return
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idx = len(t)
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pref = [v[idx] for v in t]
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indexes = trie.search(''.join(pref))
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for i in indexes:
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t.append(words[i])
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dfs(t)
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t.pop()
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trie = Trie()
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ans = []
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for i, w in enumerate(words):
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trie.insert(w, i)
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for w in words:
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dfs([w])
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return ans
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```
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### **Java**
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```java
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class Trie {
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Trie[] children = new Trie[26];
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List<Integer> v = new ArrayList<>();
105+
106+
void insert(String word, int i) {
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Trie node = this;
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for (char c : word.toCharArray()) {
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c -= 'a';
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if (node.children[c] == null) {
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node.children[c] = new Trie();
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}
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node = node.children[c];
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node.v.add(i);
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}
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}
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List<Integer> search(String pref) {
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Trie node = this;
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for (char c : pref.toCharArray()) {
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c -= 'a';
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if (node.children[c] == null) {
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return Collections.emptyList();
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}
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node = node.children[c];
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}
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return node.v;
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}
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}
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class Solution {
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private Trie trie = new Trie();
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private String[] words;
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private List<List<String>> ans = new ArrayList<>();
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public List<List<String>> wordSquares(String[] words) {
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this.words = words;
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for (int i = 0; i < words.length; ++i) {
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trie.insert(words[i], i);
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}
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List<String> t = new ArrayList<>();
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for (String w : words) {
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t.add(w);
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dfs(t);
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t.remove(t.size() - 1);
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}
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return ans;
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}
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private void dfs(List<String> t) {
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if (t.size() == words[0].length()) {
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ans.add(new ArrayList<>(t));
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return;
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}
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int idx = t.size();
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StringBuilder pref = new StringBuilder();
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for (String x : t) {
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pref.append(x.charAt(idx));
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}
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List<Integer> indexes = trie.search(pref.toString());
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for (int i : indexes) {
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t.add(words[i]);
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dfs(t);
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t.remove(t.size() - 1);
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}
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}
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}
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```
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### **Go**
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```go
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type Trie struct {
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children [26]*Trie
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v []int
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}
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func newTrie() *Trie {
180+
return &Trie{}
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}
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func (this *Trie) insert(word string, i int) {
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node := this
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for _, c := range word {
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c -= 'a'
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if node.children[c] == nil {
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node.children[c] = newTrie()
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}
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node = node.children[c]
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node.v = append(node.v, i)
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}
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}
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func (this *Trie) search(word string) []int {
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node := this
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for _, c := range word {
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c -= 'a'
197+
if node.children[c] == nil {
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return []int{}
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}
200+
node = node.children[c]
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}
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return node.v
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}
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func wordSquares(words []string) [][]string {
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trie := newTrie()
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for i, w := range words {
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trie.insert(w, i)
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}
210+
ans := [][]string{}
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var dfs func([]string)
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dfs = func(t []string) {
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if len(t) == len(words[0]) {
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cp := make([]string, len(t))
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copy(cp, t)
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ans = append(ans, cp)
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return
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}
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idx := len(t)
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pref := []byte{}
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for _, v := range t {
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pref = append(pref, v[idx])
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}
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indexes := trie.search(string(pref))
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for _, i := range indexes {
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t = append(t, words[i])
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dfs(t)
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t = t[:len(t)-1]
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}
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}
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for _, w := range words {
232+
dfs([]string{w})
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}
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return ans
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}
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```
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### **...**

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