Merge pull request #729 from amanr3085/patch-1

Create Leetcode Problem 49. Group Anagrams.java

Author: Sirajmolla

Leetcode Problem 49. Group Anagrams.java

@@ -0,0 +1,34 @@
+class Solution {
+    public List<List<String>> groupAnagrams(String[] strs) {
+         return sol2(strs);
+    }
+       public static List<List<String>> sol2(String[] str){
+        Map<String,List<String>> map = new HashMap<>();
+        for (String st : str) {
+            char[] stArr = st.toCharArray();
+            int freq[] = new int[26];
+            for (int i = 0; i < stArr.length; i++) {
+                int index = stArr[i]-'a';
+                freq[index]++;
+            }
+
+            //use Arrays.toString
+            // String stFreq = Arrays.toString(freq);
+
+            //without using Arrays.toString
+            StringBuilder sb= new StringBuilder() ;
+            for (int i = 0; i < 26; i++) {
+                sb.append(freq[i]);
+                sb.append('|');   
+            }
+            String stFreq = sb.toString();
+
+            List<String> valueList = map.getOrDefault(stFreq, new LinkedList<>());
+            valueList.add(st);
+            map.put(stFreq, valueList);
+        }
+        List<List<String>> ans = new LinkedList<>();
+        ans.addAll(map.values());
+        return ans;
+    }
+}