208. Implement Trie (Prefix Tree) | LeetCode Daily Challenge | LeetCode POTD

0:00​ - Question Understanding
4:45 - TRIE Understanding
11:40 - Code
14:45 - Complexity (Trie vs Hashmap)

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[deepintotech]

class Trie {
public:
Trie *children[26];
bool isWordEnd;
Trie() {
for (int i = 0; i < 26; i++) {
children[i] = NULL;
}
isWordEnd = false;
}

void insert(string word) {
Trie* curr = this;
for (int i = 0; i < word.length(); i++) {
char ch = word[i];
if (curr->children[ch - 'a'] == NULL) {
curr->children[ch - 'a'] = new Trie();
}
curr = curr->children[ch-'a'];
}
curr->isWordEnd = true;
}

bool search(string word) {
Trie* curr = this;
for (int i = 0; i < word.length(); i++) {
char ch = word[i];
if (curr->children[ch - 'a'] == NULL) {
return false;
}
curr = curr->children[ch - 'a'];
}
if (curr->isWordEnd == true)
return true;
return false;
}

bool startsWith(string prefix) {
Trie* curr = this;
for (int i = 0; i < prefix.length(); i++) {
char ch = prefix[i];
if (curr->children[ch - 'a'] == NULL) {
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);
*/

[muditsrivastav]

what is meaning of "this" in trie* curr = this;