Implement trie data structure in cpp

trie.cpp

@@ -0,0 +1,162 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class TrieNode {
+public:
+    unordered_map<char, unique_ptr<TrieNode>> children;
+    bool isEndOfWord;
+
+    TrieNode() : isEndOfWord(false) {}
+};
+
+class Trie {
+private:
+    unique_ptr<TrieNode> root;
+
+    // Helper method to recursively delete nodes
+    void deleteNode(TrieNode* node) {
+        if (!node) return;
+
+        for (auto& pair : node->children) {
+            deleteNode(pair.second.get());
+        }
+    }
+
+public:
+    Trie() {
+        root = make_unique<TrieNode>();
+    }
+
+    // Destructor
+    ~Trie() {
+        // Smart pointers will handle cleanup automatically
+    }
+
+    // Insert a word into the trie
+    void insert(const string& word) {
+        TrieNode* current = root.get();
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                current->children[c] = make_unique<TrieNode>();
+            }
+            current = current->children[c].get();
+        }
+
+        current->isEndOfWord = true;
+    }
+
+    // Search for a word in the trie
+    bool search(const string& word) {
+        TrieNode* current = root.get();
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c].get();
+        }
+
+        return current->isEndOfWord;
+    }
+
+    // Check if any word starts with the given prefix
+    bool startsWith(const string& prefix) {
+        TrieNode* current = root.get();
+
+        for (char c : prefix) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c].get();
+        }
+
+        return true;
+    }
+
+    // Optional: Get all words with a given prefix
+    vector<string> getWordsWithPrefix(const string& prefix) {
+        vector<string> result;
+        TrieNode* current = root.get();
+
+        // Navigate to the prefix node
+        for (char c : prefix) {
+            if (current->children.find(c) == current->children.end()) {
+                return result; // No words with this prefix
+            }
+            current = current->children[c].get();
+        }
+
+        // Collect all words from this node
+        collectWords(current, prefix, result);
+        return result;
+    }
+
+private:
+    // Helper method to collect all words from a node
+    void collectWords(TrieNode* node, const string& currentWord, vector<string>& result) {
+        if (node->isEndOfWord) {
+            result.push_back(currentWord);
+        }
+
+        for (const auto& pair : node->children) {
+            collectWords(pair.second.get(), currentWord + pair.first, result);
+        }
+    }
+};
+
+// Test function to demonstrate the Trie functionality
+void testTrie() {
+    Trie trie;
+
+    cout << "=== Trie Data Structure Test ===" << endl;
+
+    // Test insert and search
+    cout << "\n1. Testing insert and search:" << endl;
+
+    trie.insert("apple");
+    trie.insert("app");
+    trie.insert("application");
+    trie.insert("apply");
+    trie.insert("banana");
+    trie.insert("band");
+
+    cout << "Inserted words: apple, app, application, apply, banana, band" << endl;
+
+    // Test search
+    cout << "\n2. Testing search:" << endl;
+    cout << "Search 'apple': " << (trie.search("apple") ? "Found" : "Not found") << endl;
+    cout << "Search 'app': " << (trie.search("app") ? "Found" : "Not found") << endl;
+    cout << "Search 'appl': " << (trie.search("appl") ? "Found" : "Not found") << endl;
+    cout << "Search 'banana': " << (trie.search("banana") ? "Found" : "Not found") << endl;
+    cout << "Search 'orange': " << (trie.search("orange") ? "Found" : "Not found") << endl;
+
+    // Test startsWith
+    cout << "\n3. Testing startsWith:" << endl;
+    cout << "StartsWith 'app': " << (trie.startsWith("app") ? "Yes" : "No") << endl;
+    cout << "StartsWith 'appl': " << (trie.startsWith("appl") ? "Yes" : "No") << endl;
+    cout << "StartsWith 'ban': " << (trie.startsWith("ban") ? "Yes" : "No") << endl;
+    cout << "StartsWith 'ora': " << (trie.startsWith("ora") ? "Yes" : "No") << endl;
+    cout << "StartsWith 'z': " << (trie.startsWith("z") ? "Yes" : "No") << endl;
+
+    // Test getWordsWithPrefix (bonus functionality)
+    cout << "\n4. Testing getWordsWithPrefix (bonus):" << endl;
+    auto wordsWithApp = trie.getWordsWithPrefix("app");
+    cout << "Words starting with 'app': ";
+    for (const auto& word : wordsWithApp) {
+        cout << word << " ";
+    }
+    cout << endl;
+
+    auto wordsWithBan = trie.getWordsWithPrefix("ban");
+    cout << "Words starting with 'ban': ";
+    for (const auto& word : wordsWithBan) {
+        cout << word << " ";
+    }
+    cout << endl;
+}
+
+int main() {
+    testTrie();
+    return 0;
+}

trie_simple.cpp

@@ -0,0 +1,85 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class TrieNode {
+public:
+    unordered_map<char, unique_ptr<TrieNode>> children;
+    bool isEndOfWord;
+
+    TrieNode() : isEndOfWord(false) {}
+};
+
+class Trie {
+private:
+    unique_ptr<TrieNode> root;
+
+public:
+    Trie() {
+        root = make_unique<TrieNode>();
+    }
+
+    // Insert a word into the trie
+    void insert(const string& word) {
+        TrieNode* current = root.get();
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                current->children[c] = make_unique<TrieNode>();
+            }
+            current = current->children[c].get();
+        }
+
+        current->isEndOfWord = true;
+    }
+
+    // Search for a word in the trie
+    bool search(const string& word) {
+        TrieNode* current = root.get();
+
+        for (char c : word) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c].get();
+        }
+
+        return current->isEndOfWord;
+    }
+
+    // Check if any word starts with the given prefix
+    bool startsWith(const string& prefix) {
+        TrieNode* current = root.get();
+
+        for (char c : prefix) {
+            if (current->children.find(c) == current->children.end()) {
+                return false;
+            }
+            current = current->children[c].get();
+        }
+
+        return true;
+    }
+};
+
+// Example usage
+int main() {
+    Trie trie;
+
+    // Insert words
+    trie.insert("apple");
+    trie.insert("app");
+    trie.insert("application");
+    trie.insert("banana");
+
+    // Test search
+    cout << "Search 'apple': " << (trie.search("apple") ? "true" : "false") << endl;
+    cout << "Search 'app': " << (trie.search("app") ? "true" : "false") << endl;
+    cout << "Search 'appl': " << (trie.search("appl") ? "true" : "false") << endl;
+
+    // Test startsWith
+    cout << "StartsWith 'app': " << (trie.startsWith("app") ? "true" : "false") << endl;
+    cout << "StartsWith 'appl': " << (trie.startsWith("appl") ? "true" : "false") << endl;
+    cout << "StartsWith 'ban': " << (trie.startsWith("ban") ? "true" : "false") << endl;
+
+    return 0;
+}