B树的查找

BTNode* searchBTree(BTree T, keytype  k, int* pos) {
    int i;
    BTNode* p = T;
    while (p != NULL) {
        i = p->keynum;
        p->key[0] = k;
        while (k < p->key[i])
            i--;
        if (k == key[i] && i > 0) {
            pos = i;
            return p;
        }
        else
            p = p->prt[i];
    }
    return NULL;
}