릿코드 872. Leaf-Similar Trees 코틀린

노드순회하면서 리프면 배열에 추가후 비교
재귀사용


정답

class Solution {
    fun leafSimilar(root1: TreeNode?, root2: TreeNode?): Boolean {
        return leftFirstTreeLeafSearch(root1)==leftFirstTreeLeafSearch(root2)
    }
    fun leftFirstTreeLeafSearch(root1: TreeNode?):List<Int>{
        val tempList = mutableListOf<Int>()
        if (root1==null){
            throw IllegalArgumentException()
        }
        if (root1.left==null && root1.right==null){
            tempList.add(root1.`val`)
        }
        if(root1.left!=null){
            tempList.addAll( leftFirstTreeLeafSearch(root1.left))
        }
        if(root1.right!=null){
            tempList.addAll( leftFirstTreeLeafSearch(root1.right))
        }
        return tempList
    }
}