56 lines
1.4 KiB
C++
56 lines
1.4 KiB
C++
class Trie {
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public:
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struct Node
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{
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bool ends;
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Node* next[26];
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Node()
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{
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ends = false;
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memset(next, 0, sizeof(next));
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}
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};
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Node* root;
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Trie() {
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root = new Node;
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}
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inline void stepDownInsert(const string& word, int index, Node* current) {
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if (index >= word.size()) {
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current->ends = true;
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return;
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}
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if (!current->next[word[index] - 'a']) {
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current->next[word[index] - 'a'] = new Node;
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}
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stepDownInsert(word, index + 1, current->next[word[index] - 'a']);
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}
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void insert(string word) {
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stepDownInsert(word, 0, root);
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}
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inline bool stepDownSearch(const string& word, int index, Node* current) {
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if (index >= word.size()) return current->ends;
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if (current->next[word[index] - 'a']) return stepDownSearch(word, index + 1, current->next[word[index] - 'a']);
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return false;
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}
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bool search(string word) {
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return stepDownSearch(word, 0, root);
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}
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inline bool stepDownPrefix(const string& word, int index, Node* current) {
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if (index >= word.size()) return true;
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if (current->next[word[index] - 'a']) return stepDownPrefix(word, index + 1, current->next[word[index] - 'a']);
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return false;
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}
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bool startsWith(string prefix) {
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return stepDownPrefix(prefix, 0, root);
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}
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};
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