题解 | #对称的二叉树#递归实现判断

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;
        }
        return isSymmetrical(pRoot.left,pRoot.right);
    }
    boolean isSymmetrical(TreeNode left,TreeNode right){
        if(left == null && right == null){
            return true;
        }
        if(left == null || right == null){//一边为空一边不为空
            return false;
        }
        boolean res = left.val == right.val &&  isSymmetrical(left.left,right.right) && isSymmetrical(left.right,right.left);
        return res;
        
    }
}