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@vitkarpov
Created March 19, 2020 07:55
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class Trie {
private:
struct Node {
vector<Node*> children = vector<Node*>(26);
bool is_word = false;
};
Node* root = new Node;
public:
/** Initialize your data structure here. */
Trie() {}
/** Inserts a word into the trie. */
void insert(string word) {
auto curr = root;
for (auto ch : word) {
if (!curr->children[ch - 'a']) {
curr->children[ch - 'a'] = new Node;
}
curr = curr->children[ch - 'a'];
}
curr->is_word = true;
}
/** Returns if the word is in the trie. */
bool search(string word) {
auto curr = root;
for (auto ch : word) {
if (!curr->children[ch - 'a']) {
return false;
}
curr = curr->children[ch - 'a'];
}
return curr->is_word;
}
/** Returns if there is any word in the trie that starts with the given prefix. */
bool startsWith(string prefix) {
auto curr = root;
for (auto ch : prefix) {
if (!curr->children[ch - 'a']) {
return false;
}
curr = curr->children[ch - 'a'];
}
return true;
}
};
/**
* Your Trie object will be instantiated and called as such:
* Trie* obj = new Trie();
* obj->insert(word);
* bool param_2 = obj->search(word);
* bool param_3 = obj->startsWith(prefix);
*/
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