classSolution {

funlargestValues(root:TreeNode?):List<Int> {

val res= mutableListOf<Int>()

root?:return res

with (LinkedList<TreeNode?>()) {

addLast(root)

while (isNotEmpty()) {

var levelMax= peekLast()!!.`val`

repeat (size) {

val cur= removeFirst()

levelMax= maxOf(levelMax, cur!!.`val`)

cur?.left?.let { addLast(it) }

cur?.right?.let { addLast(it) }

}

res.add(levelMax)

}

}

return res

}

}

classSolution {

funlargestValues(root:TreeNode?):List<Int> {

root?:return listOf<Int>()

val maxes=HashMap<Int,Int>()

fundfs(cur:TreeNode?,level:Int) {

cur?:return

maxes[level]= maxOf(

cur?.value?:Integer.MIN_VALUE,

maxes.getOrDefault(level,Integer.MIN_VALUE)

)

dfs(cur?.left, level+1)

dfs(cur?.right, level+1)

}

dfs(root,0)

return maxes.values.toList()

}

valTreeNode.value

get()=this.`val`

}