题解 | #相逆叶子#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 *   public TreeNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param root1 TreeNode类 
     * @param root2 TreeNode类 
     * @return bool布尔型
     */
    public boolean leafSimilar (TreeNode root1, TreeNode root2) {
        // write code here
        List<Integer> list1 = new ArrayList<>();
        List<Integer> list2 = new ArrayList<>();
        collectLeaf(root1, list1, "left");
        collectLeaf(root2, list2, "right");
        if(list1.size() != list2.size()) return false;
        for(int i = 0; i < list1.size(); i++){
            if(list1.get(i) != list2.get(i)) return false;
        }
        return true;
    }
    private void collectLeaf(TreeNode root, List<Integer> list, String mark){
        if(root == null) return;
        if(root.left == null && root.right == null) {
            list.add(root.val);
            return;
        }
        if("left".equals(mark)){
            collectLeaf(root.left, list, "left");
            collectLeaf(root.right, list, "left");
        }else{
            collectLeaf(root.right, list, "right");
            collectLeaf(root.left, list, "right");
        }
    }
        
}