题解 | #对称的二叉树#

/*
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 t1,TreeNode t2){
        if (t1 == null && t2 == null){
            return true;
        }
        if (t1 == null || t2 == null){
            return false;
        }
        if (t1.val != t2.val){
            return false;
        }
        return isSymmetrical(t1.left, t2.right) && isSymmetrical(t1.right, t2.left);
    }

}