Record brushing questions-(leetcode-101 symmetrical binary tree)

Problem: Given a binary tree, check whether it is mirror-symmetrical.
For example, the binary tree [1,2,2,3,4,4,3] is symmetric.
1
/
22
/ \ /
3443
Source: stay button (LeetCode)
link: https: //leetcode-cn.com/problems/symmetric-tree
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Code:

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
bool is_symmetric(struct TreeNode* root1,struct TreeNode* root2){
    
    
    if(!root1&&!root2)
        return true;
    if(!root1||!root2){
    
    
        return false;
    }
    if(root1->val==root2->val){
    
    
        return is_symmetric(root1->left,root2->right)&&is_symmetric(root1->right,root2->left);
    }
    return false;
}
bool isSymmetric(struct TreeNode* root){
    
    
    return is_symmetric(root,root);
}