对称二叉树 - lifengyu360/lifengyu_first_git_test GitHub Wiki
class Solution {
public:
bool check(TreeNode *p, TreeNode *q) {
if (!p && !q) return true;
if (!p || !q) return false;
return p->val == q->val && check(p->left, q->right)&&check(p->right, q->left);
}
bool isSymmetric(TreeNode* root) {
return check(root, root);
}
};