题解 | #相逆叶子#

知识点：层序遍历

思路：拿到叶子节点就行了，层序遍历是其中的一种方式，当然你可以用其他的方式，我这里用两个栈来存储叶子节点

编程语言：java

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) {
        Stack<Integer> stack1 = new Stack<>();
        Stack<Integer> stack2 = new Stack<>();

        pushLeftLeaves(root1, stack1);
        pushRightLeaves(root2, stack2);

        return stack1.equals(stack2);
    }

    private void pushLeftLeaves(TreeNode node, Stack<Integer> stack) {
        if (node != null) {
            if (node.left == null && node.right == null) {
                stack.push(node.val);
            } else {
                pushLeftLeaves(node.left, stack);
                pushLeftLeaves(node.right, stack);
            }
        }
    }

    private void pushRightLeaves(TreeNode node, Stack<Integer> stack) {
        if (node != null) {
            if (node.left == null && node.right == null) {
                stack.push(node.val);
            } else {
                pushRightLeaves(node.right, stack);
                pushRightLeaves(node.left, stack);
            }
        }
    }
}