问题:
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.
分析:
考虑使用深度优先遍历的方法,同时遍历两棵树,遇到不等的就返回。
代码如下:
/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public boolean isSameTree(TreeNode p, TreeNode q) {
if(p == null || q==null){
return p==q;
}
if(p.val != q.val){
return false;
}
return isSameTree(p.left,q.left)&& isSameTree(p.right,q.right);
}
}