Implement trie data structure for string operations

trie.cpp

@@ -0,0 +1,98 @@
+#include <iostream>
+#include <string>
+#include <unordered_map>
+using namespace std;
+
+class Trie {
+private:
+    struct TrieNode {
+        unordered_map<char, TrieNode*> children;
+        bool isEndOfWord;
+
+        TrieNode() : isEndOfWord(false) {}
+    };
+
+    TrieNode* root;
+
+public:
+    Trie() {
+        root = new TrieNode();
+    }
+
+    void insert(string word) {
+        TrieNode* current = root;
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                current->children[c] = new TrieNode();
+            }
+            current = current->children[c];
+        }
+
+        current->isEndOfWord = true;
+    }
+
+    bool search(string word) {
+        TrieNode* current = root;
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c];
+        }
+
+        return current->isEndOfWord;
+    }
+
+    bool startsWith(string prefix) {
+        TrieNode* current = root;
+
+        for (char c : prefix) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c];
+        }
+
+        return true;
+    }
+
+    // Destructor to clean up memory
+    ~Trie() {
+        deleteTrie(root);
+    }
+
+private:
+    void deleteTrie(TrieNode* node) {
+        if (node == nullptr) return;
+
+        for (auto& pair : node->children) {
+            deleteTrie(pair.second);
+        }
+
+        delete node;
+    }
+};
+
+// Example usage and test cases
+int main() {
+    Trie trie;
+
+    // Test insert and search
+    trie.insert("apple");
+    cout << "Search 'apple': " << (trie.search("apple") ? "true" : "false") << endl;
+    cout << "Search 'app': " << (trie.search("app") ? "true" : "false") << endl;
+
+    // Test startsWith
+    cout << "StartsWith 'app': " << (trie.startsWith("app") ? "true" : "false") << endl;
+
+    // Insert more words
+    trie.insert("app");
+    trie.insert("application");
+
+    cout << "Search 'app' after insert: " << (trie.search("app") ? "true" : "false") << endl;
+    cout << "StartsWith 'appl': " << (trie.startsWith("appl") ? "true" : "false") << endl;
+
+    return 0;
+}