LeetCode 101 对称二叉树
/**
Definition for a binary tree node.
public class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode() {}
TreeNode(int val) { this.val = val; }
TreeNode(int val, TreeNode left, TreeNode right) {
this.val = val;
this.left = left;
this.right = right;
}
}
*/
class Solution {
public boolean isSymmetric(TreeNode root) {
return def(root,root);
}
public boolean def(TreeNode left,TreeNode right){
if(leftnull&&rightnull){
return true;
}if(left == null||right == null){
return false;
}if(left.val!=right.val){
return false;
}if(!def(left.left,right.right)){
return false;
}else{
return def(left.right,right.left);
}
}
}
总结
树节点不能进行值的比较，也返回不了boolean值，得用树结构调用里面的属性进行值的比较，之后返回比较结果的一个boolean值！！！！
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