add new solutions

solutions/8/q865/solution.go

@@ -0,0 +1,35 @@
+package q865
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func search(node *TreeNode, depth int) (*TreeNode, int) {
+	if node == nil {
+		return nil, 0
+	}
+
+	if node.Left == nil && node.Right == nil {
+		return node, depth
+	}
+
+	ln, ld := search(node.Left, depth+1)
+	rn, rd := search(node.Right, depth+1)
+	switch {
+	case ld == rd:
+		return node, ld
+	case ld < rd:
+		return rn, rd
+	default:
+		return ln, ld
+	}
+}
+
+func subtreeWithAllDeepest(root *TreeNode) *TreeNode {
+	node, _ := search(root, 1)
+	return node
+}
+
+var _ = subtreeWithAllDeepest