CSCI 335 Fourth assignment solved




Priority queues (100 points) You are asked to implement a binomial queue (bq) linked with a hash-table. You can use code provided in the textbook. The bq is used for fast access of the minimum element and the hash-table for fast access within the elements in the bq. (1) Implement the binomial queue. For testing use the strings in the document file used in the previous assignment. These would be the keys to be inserted into the priority queue. Implement a hash-table of the keys that are already in the priority queue. So, for any pair <key,p>, where p is the pointer of the the node that holds key in the priority queue, hash on the key, and store the pair <key,p> in your hash table. Also note that for every insertion, deleteMin, or merge the hash-table needs to be updated as well. As part of this implementation you have to create a private function find( key). This function will return the pointer p that points to the node of bq that holds the key, or nullptr if key is not in the bq. (2) Count and print out the total number of comparisons and assignments executed for the insertions of all the N elements into the binomial queue. (3) Test the deleteMin() operation by applying a sequence of 10 deleteMin() and by printing out the result. (4) Test the function find() as follows: Prompt the user to input a string key. Execute the private function find(key). If find returns a pointer to a node that indeed holds key printout that find() was successful. Otherwise, printout that find() did not find the key. (5) You are ready to implement now the remove(key) operation. For a given key, find its position p (p is a pointer) in the priority queue using the hash table. If the key is found delete it from the bq (Hint: your code should percolate the key up all the way to the root and then delete the root). Test your implementation by applying a sequence of remove(key) operations, and verify their correctness. For instance after remove(key), find(key) should return “not found”. Prompt the user 5 times to input a key. Execute then the remove(key) operation and verify (by printing whether the removal was successful or not). (6) Write a faster insert(key) function for the binomial queue. In order to achieve that you have to modify the merge() function and make it specific to the merging of one element only.