Question

Can someone implement this using singly linked list. Please and thank you

public interface PriorityQueueInterface<T extends Comparable<T>>
{
/** * Adds a new entry to this priority queue * @param newEntry An object to be added. */
void add(T newEntry);
/** Removes and returns the entry having the highest priority. * @return Either the object having the highest priority or, if the priority * queue is empty before the operation, null. */
T remove();
/** Retrieves the entry having the highest priority. * @return Either the object having the highest priority or, if the priority * queue is empty, null. */
T peek();
/** Detects whether this priority queue is empty. * @return True if the priority queue is empty, or false otherwise. */
boolean isEmpty();
/** Gets the size of this priority queue * @return The number of entries currently in the priority queue. */
int getSize();
/** Removes all entries from this priority queue. */
void clear(); }

Answer 1

Structure

typedef struct node {

    int data;
    int priority; // Low values means higher priority

    struct node* next;

  } Node;

  

Add

Node* newNode(int d, int p)

{

    Node* t= (Node*)malloc(sizeof(Node));

    t->data = d;

    t->priority = p;

    t->next = NULL;

    return t;

}

  void push(Node** head, int d, int p)

{

    Node* start = (*head);

    Node* temp = newNode(d, p);

  

    if ((*head)->priority > p) {     // if head has less priority than new node  

        temp->next = *head;

        // Insert New Node before head

        (*head) = temp;

    }

    else {

        // Traverse to find position to insert new node

        while (start->next != NULL &&

               start->next->priority < p) {

            start = start->next;

        }

        temp->next = start->next;

        start->next = temp;

    }

}

Remove

// Remove the highest priority and return

Node* remove(Node** head)

{

    Node* temp = *head;

    (*head) = (*head)->next;

    return temp;

}

PEEK

int peek(Node** head)

{

    return (*head)->data; }

isEmpty

boolean isEmpty(Node** head){

if (head) return 1;

else return 0;

}

GETSIZE  

int getSize(Node** head){

Node* start = (*head); int c=1;

while (start->next != NULL ) {

            start = start->next; c++;

        } return c;

}

CLEAR

//clear all values

void clear(Node** head){

Node* start = (*head);

while (start->next != NULL ) {

Node *t=start;

            start = start->next; free(t);

        } *head=NULL;

}