Create 08_trie.cpp

10 October LeetCode Challenge 2021/08_trie.cpp

@@ -0,0 +1,36 @@
+class Trie {
+public:
+    Trie* children[26] = {};
+    bool isWord = false;
+
+    void insert(string word) {
+        Trie* cur = this;
+        for (char c : word) {
+            c -= 'a';
+            if (cur->children[c] == nullptr)
+                cur->children[c] = new Trie();
+            cur = cur->children[c];
+        }
+        cur->isWord = true;
+    }
+
+    bool search(string word) {
+        Trie* cur = this;
+        for (char c : word) {
+            c -= 'a';
+            if (cur->children[c] == nullptr) return false;
+            cur = cur->children[c];
+        }
+        return cur->isWord;
+    }
+
+    bool startsWith(string prefix) {
+        Trie* cur = this;
+        for (char c : prefix) {
+            c -= 'a';
+            if (cur->children[c] == nullptr) return false;
+            cur = cur->children[c];
+        }
+        return true;
+    }
+};