2024-04-16 19:16:34 +0000 UTC

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func addOneRow(root *TreeNode, val int, depth int) *TreeNode {
    if root == nil {
        return nil
    }

    if depth == 1 {
        root = &TreeNode{Val: val, Left: root}
    } else if (depth == 2) {
        root.Left = &TreeNode{Val: val, Left: root.Left}
        root.Right = &TreeNode{Val: val, Right: root.Right}
    } else {
        addOneRow(root.Left, val, depth - 1)
        addOneRow(root.Right, val, depth - 1)
    }

    return root;
}