100. Same Tree100. Same Tree

题目描述

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.

解题方法

比較架構

case 1:  當同為遇到null, 返true

case 2:  一則為空，返false

比較數值

確認data是否相同

public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p == null && q == null){
            return true;
        }
        //一方為空一方不為空
        if(p == null || q == null){
            return false;    
        }

        //值不相同
        if(p.val != q.val){
            return false;
        }

        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }