[Add LeetCode submission] - Group Anagrams (49) (golang)

Author: lootek

Group Anagrams (49)/README.md

@@ -18,19 +18,19 @@ Medium
 
 [solution.go](solution.go)
 
-[LeetCode submissions section](https://leetcode.com/problems/group-anagrams/submissions/1615992382/)
+[LeetCode submissions section](https://leetcode.com/problems/group-anagrams/submissions/1616019720/)
 
 ### Performance
 
-[LeetCode submission details](https://leetcode.com/submissions/detail/1615992382/)
+[LeetCode submission details](https://leetcode.com/submissions/detail/1616019720/)
 
 #### CPU
 
-Took 18 ms (beats 21.57%)
+Took 9 ms (beats 73.90%)
 
 #### Memory
 
-Used 10 MB (beats 41.11%)
+Used 9.5 MB (beats 72.15%)
 
 ## Problem statement
 

Group Anagrams (49)/solution.go

@@ -1,20 +1,25 @@
 func groupAnagrams(strs []string) [][]string {
-    wordsMap := map[string][]string{}
+	wordsMap := map[string]int{}
+    res := [][]string{}
+	cnt := 0
+	for _, word := range strs {
+		normalizedArr := []byte(word)
+		sort.Slice(normalizedArr, func(i, j int) bool {
+			return normalizedArr[i] < normalizedArr[j]
+		})
+		normalized := string(normalizedArr)
 
-    for _, word := range strs {
-        normalizedArr := strings.Split(word, "")
-        sort.Strings(normalizedArr)
-        normalized := strings.Join(normalizedArr, "")
+		id, ok := wordsMap[normalized]
+        if !ok {
+            id = cnt
+            wordsMap[normalized] = id
+            res = append(res, []string{})
 
-        anagrams := wordsMap[normalized]
-        anagrams = append(anagrams, word)
-        wordsMap[normalized] = anagrams
-    }
+			cnt++
+		}
 
-    res := [][]string{}
-    for _, list := range wordsMap {
-        res = append(res, list)
-    }
+		res[id] = append(res[id], word)
+	}
 
-    return res
+	return res
 }