add new solutions

solutions/7/q700/solution.go

@@ -0,0 +1,24 @@
+package q700
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func searchBST(root *TreeNode, val int) *TreeNode {
+	if root == nil {
+		return nil
+	}
+
+	switch {
+	case val == root.Val:
+		return root
+	case val > root.Val:
+		return searchBST(root.Right, val)
+	default:
+		return searchBST(root.Left, val)
+	}
+}
+
+var _ = searchBST