100. Same Tree

https://leetcode.com/problems/same-tree/description/
Try to simplify the code.
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(!p || !q) return p == q;
        return 
            (p->val == q->val) &&
            isSameTree(p->left, q->left) && 
            isSameTree(p->right, q->right);
    }