add new solutions

solutions/12/q1207/solution.go

@@ -0,0 +1,25 @@
+package q1207
+
+import "slices"
+
+type void struct{}
+
+func uniqueOccurrences(arr []int) bool {
+	slices.Sort(arr)
+	seen := map[int]void{}
+
+	for i := 0; i < len(arr); {
+		c := arr[i]
+		count := 0
+		for ; i < len(arr) && arr[i] == c; i++ {
+			count++
+		}
+		if _, ok := seen[count]; ok {
+			return false
+		}
+		seen[count] = void{}
+	}
+	return true
+}
+
+var _ = uniqueOccurrences