题解 | #对称的二叉树#

前序遍历 和 对称前序遍历

/*
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) {
        return isSymmetrical(pRoot, pRoot);
    }
    
    boolean isSymmetrical(TreeNode node1, TreeNode node2) {
        if(node1 == null && node2 == null){
            return true;
        }
        
        if(node1 == null || node2 == null){
            return false;
        }
        
        if(node1.val != node2.val){
            return false;
        }
        
        return isSymmetrical(node1.left,node2.right) && isSymmetrical(node1.right, node2.left);
    }
}