题解 | #对称的二叉树#

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};
*/
class Solution {
  public:
    bool fl = true;
    void dfs(TreeNode* le, TreeNode* ri) {
        if(le==nullptr&&ri==nullptr)return;
        if ((le == nullptr ^ ri == nullptr) || le->val != ri->val) {
            fl = false;
            return;
        }
        dfs(le->left, ri->right), dfs(le->right, ri->left);
    }
    bool isSymmetrical(TreeNode *pRoot) {
        if (pRoot != nullptr)dfs(pRoot->left, pRoot->right);
        return fl;
    }

};