add new solutions

solutions/6/q645/solution.go

@@ -0,0 +1,22 @@
+package q645
+
+func findErrorNums(nums []int) []int {
+	var duplicated, missing int
+	seen := make([]bool, len(nums))
+
+	for _, n := range nums {
+		if seen[n-1] {
+			duplicated = n
+		}
+		seen[n-1] = true
+	}
+	for i, ok := range seen {
+		if !ok {
+			missing = i + 1
+			break
+		}
+	}
+	return []int{duplicated, missing}
+}
+
+var _ = findErrorNums