add sol

leetcode/623.AddOneRowtoTree/sol.go

@@ -0,0 +1,44 @@
+// https://leetcode.com/problems/add-one-row-to-tree/
+
+package main
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func addOneRow(root *TreeNode, val int, depth int) *TreeNode {
+	if depth == 1 {
+		return &TreeNode{val, root, nil}
+	}
+	q := []*TreeNode{root}
+	i := 0
+	for len(q) > 0 {
+		i++
+		for k := len(q); k > 0; k-- {
+			node := q[0]
+			q = q[1:]
+			if node.Left != nil {
+				q = append(q, node.Left)
+			}
+			if node.Right != nil {
+				q = append(q, node.Right)
+			}
+			if i == depth-1 {
+				node.Left = &TreeNode{val, node.Left, nil}
+				node.Right = &TreeNode{val, nil, node.Right}
+			}
+		}
+	}
+	return root
+}