anagram

Author: Simcoderan

Medium49.java

@@ -0,0 +1,38 @@
+import java.util.*;
+
+public class Medium49 {
+    public List<List<String>> groupAnagrams(String[] strs) {
+        if (strs.length == 0) {
+            return new ArrayList<>();
+        }
+
+        // Use proper generic types for type safety
+        Map<String, List<String>> ansMap = new HashMap<>();
+
+        int[] count = new int[26];
+        
+        for (String s : strs) {
+            Arrays.fill(count, 0);  // Reset count array for each string
+            
+            // Count the frequency of each character
+            for (char c : s.toCharArray()) {
+                count[c - 'a']++;
+            }
+
+            // Create a unique key based on the character counts
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < 26; i++) {
+                sb.append("#");
+                sb.append(count[i]);
+            }
+            String key = sb.toString();
+
+            // If the key doesn't exist, create a new list
+            ansMap.putIfAbsent(key, new ArrayList<>());
+            ansMap.get(key).add(s);
+        }
+
+        // Return the grouped anagrams as a list of lists
+        return new ArrayList<>(ansMap.values());
+    }
+}