Two-Hundred-Sixteen Commit: Add Search Suggestions System problem to Trie Section

Author: AAdewunmi

src/Trie/Problem_5_Search_Suggestions_System.java

@@ -0,0 +1,85 @@
+package Trie;
+
+// Problem Statement: Search Suggestions System (medium)
+// LeetCode Question: 1268. Search Suggestions System
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Problem_5_Search_Suggestions_System {
+
+    class TrieNode {
+        TrieNode[] children = new TrieNode[26];
+        boolean isEnd = false;
+    }
+
+    class Trie {
+        TrieNode root;
+
+        Trie() {
+            root = new TrieNode();
+        }
+
+        // Inserts a word into the trie
+        void insert(String word) {
+            TrieNode node = root;
+            for (char ch : word.toCharArray()) {
+                if (node.children[ch - 'a'] == null) {
+                    node.children[ch - 'a'] = new TrieNode();
+                }
+                node = node.children[ch - 'a'];
+            }
+            node.isEnd = true;
+        }
+
+        // Performs a DFS to find all words with the given prefix
+        void dfs(TrieNode node, List<String> list, StringBuilder word) {
+            if (list.size() == 3) return; // Limit to 3 suggestions
+            if (node.isEnd) {
+                list.add(word.toString());
+            }
+
+            for (char ch = 'a'; ch <= 'z'; ch++) {
+                if (node.children[ch - 'a'] != null) {
+                    word.append(ch);
+                    dfs(node.children[ch - 'a'], list, word);
+                    word.deleteCharAt(word.length() - 1);
+                }
+            }
+        }
+
+        // Searches the trie for words starting with prefix
+        List<String> search(String prefix) {
+            TrieNode node = root;
+            List<String> list = new ArrayList<>();
+
+            for (char ch : prefix.toCharArray()) {
+                if (node.children[ch - 'a'] == null) {
+                    return list; // No words found with this prefix
+                }
+                node = node.children[ch - 'a'];
+            }
+
+            dfs(node, list, new StringBuilder(prefix));
+            return list;
+        }
+    }
+
+    public List<List<String>> suggestedProducts(String[] products, String searchWord) {
+        Trie trie = new Trie();
+        for (String product : products) {
+            trie.insert(product);
+        }
+
+        List<List<String>> result = new ArrayList<>();
+        StringBuilder prefix = new StringBuilder();
+
+        for (char ch : searchWord.toCharArray()) {
+            prefix.append(ch);
+            result.add(trie.search(prefix.toString()));
+        }
+
+        return result;
+    }
+
+}