题目
/*
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution {
boolean isSymmetrical(TreeNode pRoot)
{
if(pRoot == null) return true; //判断为空
return comparenode(pRoot.left,pRoot.right);
}
private boolean comparenode(TreeNode left,TreeNode right){
if(left == null && right == null){ // 结束
return true;
}
if(left !=null && right != null){
if(left.val == right.val){
if(comparenode(left.left,right.right)&&comparenode(left.right,right.left)){ // 同时比较两端
return true;
}
}
}
return false;
}
}
