boolean isSymmetrical(TreeNode pRoot) { if(pRoot==null) return true; TreeNode pLeft = pRoot.left; TreeNode pRight = pRoot.right; boolean res = help(pLeft,pRight); return res; } public boolean help(TreeNode pLeft,TreeNode pRight){ if(pLeft==null && pRight==null )return true; //下面是两种不对称的情况:一是左...