add LC-617

Signed-off-by: Tahsin Tunan <[email protected]>

Author: tahsintunan

go/0617-merge-two-binary-trees.go

@@ -0,0 +1,26 @@
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func mergeTrees(root1 *TreeNode, root2 *TreeNode) *TreeNode {
+	if root1 == nil && root2 == nil {
+		return nil
+	}
+	if root1 == nil {
+		return root2
+	}
+	if root2 == nil {
+		return root1
+	}
+
+	var node TreeNode
+	node.Val = root1.Val + root2.Val
+	node.Left = mergeTrees(root1.Left, root2.Left)
+	node.Right = mergeTrees(root1.Right, root2.Right)
+
+	return &node
+}