contains-duplicate: adjust init size

Author: Invidam

contains-duplicate/invidam.go

@@ -1,5 +1,5 @@
 func containsDuplicate(nums []int) bool {
-	appeared := make(map[int]bool, len(nums))
+	appeared := make(map[int]bool, len(nums)/4)
 
 	for _, num := range nums {
 		if _, found := appeared[num]; found {