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.
解题思路
一个queue解决一层一层比较
Java代码实现
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public boolean isSameTree(TreeNode p, TreeNode q) {
Queue<TreeNode> nodeQueue = new LinkedList<>();
nodeQueue.offer(p);
nodeQueue.offer(q);
while (!nodeQueue.isEmpty()) {
TreeNode node1 = nodeQueue.poll();
TreeNode node2 = nodeQueue.poll();
if (node1 == null && node2 != null || node1 != null && node2 == null) {
return false;
} else if (node1 == null || node2 == null) {
continue;
} else {
if (node1.val == node2.val) {
nodeQueue.offer(node1.left);
nodeQueue.offer(node2.left);
nodeQueue.offer(node1.right);
nodeQueue.offer(node2.right);
} else {
return false;
}
}
}
return true;
}
}
