ex3.12: better performance

ex3.12/anagram.go

@@ -2,21 +2,19 @@
 package anagram
 
 func isAnagram(a, b string) bool {
-	aFreq := make(map[rune]int)
+	if len(a) != len(b) {
+		return false
+	}
+
+	freq := make(map[rune]int)
 	for _, c := range a {
-		aFreq[c]++
+		freq[c]++
 	}
-	bFreq := make(map[rune]int)
 	for _, c := range b {
-		bFreq[c]++
-	}
-	for k, v := range aFreq {
-		if bFreq[k] != v {
-			return false
-		}
+		freq[c]--
 	}
-	for k, v := range bFreq {
-		if aFreq[k] != v {
+	for _, v := range freq {
+		if v != 0 {
 			return false
 		}
 	}