/* public class TreeNode { int val = 0; TreeNode left = null; TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
} */ //别想那么复杂,越简单越好 public class Solution { boolean isSymmetrical(TreeNode pRoot) { if(pRoot == null) return true;
if(isEqual(pRoot.left, pRoot.right)) return true;
return false;
}
private boolean isEqual(TreeNode t1,TreeNode t2) {
if(t1==null && t2==null) return true;
if(t1==null && t2!=null) return false;
if(t1!=null && t2==null) return false;
if(t1.val == t2.val) {
if(isEqual(t1.left, t2.right) && isEqual(t1.right, t2.left)) return true;
}
return false;
}
}