LeetCode 100 Same Tree

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
    if(p==NULL && q==NULL)
        return true;
    else if(p==NULL || q==NULL)
        return false;
    return p->val==q->val && (isSameTree(p->left,q->left) && isSameTree(p->right,q->right));
}