package q199

type TreeNode struct {
	Val   int
	Left  *TreeNode
	Right *TreeNode
}

func rightSideView(root *TreeNode) []int {
	ret := []int{}

	type qElem struct {
		height int
		node   *TreeNode
	}

	queue := []qElem{{0, root}}
	var last *qElem
	for ; len(queue) > 0; queue = queue[1:] {
		cur := &queue[0]
		if cur.node == nil {
			continue
		}
		if last != nil && last.height < cur.height {
			ret = append(ret, last.node.Val)
		}
		last = cur
		queue = append(queue, qElem{cur.height + 1, cur.node.Left}, qElem{cur.height + 1, cur.node.Right})
	}
	if last != nil {
		ret = append(ret, last.node.Val)
	}

	return ret
}

var _ = rightSideView