【leetcode】从根到叶的二进制数之和

void trans(struct TreeNode* root, int cur, int *sum)
{
    if (root == NULL) {
        return;
    }
    cur = cur * 2 + root->val;
    if (root->left == NULL && root->right == NULL) {
        *sum = (*sum + cur) % ((int)pow(10,9) + 7);
        return;
    }
    trans(root->left, cur, sum);
    trans(root->right, cur, sum);
    return;
}
int sumRootToLeaf(struct TreeNode* root){
    int sum = 0;
    trans(root, 0, &sum);
    return sum;
}