add new solutions

solutions/2/q206/solution.go

@@ -0,0 +1,18 @@
+package q206
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func reverseList(head *ListNode) *ListNode {
+	var prev, current *ListNode = nil, head
+	for current != nil {
+		next := current.Next
+		current.Next = prev
+		prev, current = current, next
+	}
+	return prev
+}
+
+var _ = reverseList