LeetCode题解：Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

题意：给定两颗二叉树，判断它们是否相同

解题思路：层次遍历

代码：

public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        boolean result = false;

        if(p == null && q == null){
            return true;
        }

        if(p == null ||q == null){
            return false;
        }

        Queue<TreeNode> pQueue = new LinkedList<TreeNode>();
        Queue<TreeNode> qQueue = new LinkedList<TreeNode>();

        pQueue.add(p);
        qQueue.add(q);
        while(!pQueue.isEmpty() && !qQueue.isEmpty()){
            TreeNode tempP = pQueue.poll();
            TreeNode tempQ = qQueue.poll();

            if(tempP == null && tempQ == null){
                result = true;
            }

            if(tempP == null || tempQ ==null){
                result = false;
            }

            if(tempP.val != tempQ.val){
                result = false;
                break;
            }else{
                result = true;
            }

            if(tempP.left != null){
                pQueue.add(tempP.left);
            }

            if(tempP.right != null){
                pQueue.add(tempP.right);
            }

            if(tempQ.left != null){
                qQueue.add(tempQ.left);
            }

            if(tempQ.right != null){
                qQueue.add(tempQ.right);
            }

            if(pQueue.size() != qQueue.size()){
                result = false;
                break;
            }
        }

        return result;
    }
}