add new solutions

solutions/10/q1009/solution.go

@@ -0,0 +1,12 @@
+// Package q1009 implements a solution for https://leetcode.com/problems/complement-of-base-10-integer/
+package q1009
+
+func bitwiseComplement(n int) int {
+	i := 1
+	for i <= n {
+		i <<= 1
+	}
+	return n ^ max(i-1, 1)
+}
+
+var _ = bitwiseComplement