Question

Language C++ (Please include a short description & Screenshot of output)

Implement a Priority queue using a SORTED list. Use Quick sort after adding a new node.

Example of quick sort below. Adopt to your program the code below.

#include <iostream>

void quickSort(int a[ ], int first, int last);

int pivot(int a[], int first, int last);

void swap(int& a, int& b);

void swapNoTemp(int& a, int& b);

void print(int array[], const int& N);

using namespace std;

int main() {

int test[] = { 7, -13, 1, 3, 10, 5, 2, 4 };

int N = sizeof(test)/sizeof(int);

cout << "Size of test array :" << N << endl;

cout << "Before sorting : " << endl;

print(test, N);

quickSort(test, 0, N-1);

cout << endl << endl << "After sorting : " << endl; print(test, N);

return 0; }

/**

* Quicksort.

* @param a - The array to be sorted.

* @param first - The start of the sequence to be sorted.

* @param last - The end of the sequence to be sorted.

*/

void quickSort( int a[], int first, int last ) {

int pivotElement;

if(first < last) {

pivotElement = pivot(a, first, last);

quickSort(a, first, pivotElement-1);

quickSort(a, pivotElement+1, last); }

}

/**

* Find and return the index of pivot element.

* @param a - The array.

* @param first - The start of the sequence.

* @param last - The end of the sequence.

* @return - the pivot element

*/

int pivot(int a[], int first, int last) {

int p = first;

int pivotElement = a[first];

for(int i = first+1 ; i++) {

/* If you want to sort the list in the other order, change "" */ if(a[i] <= pivotElement) {

p++; swap(a[i], a[p]);

}

}

swap(a[p], a[first]);

return p; }

/**

* Swap the parameters.

* @param a - The first parameter.

* @param b - The second parameter.

*/

void swap(int& a, int& b) {

int temp = a;

a = b;

b = temp; }

/**

* Swap the parameters without a temp variable.

* Warning! Prone to overflow/underflow.

* @param a - The first parameter.

* @param b - The second parameter.

*/

void swapNoTemp(int& a, int& b) {

a -= b;

b += a;// b gets the original value of a

a = (b - a);// a gets the original value of b }

/**

* Print an array.

* @param a - The array.

* @param N - The size of the array.

*/ void print(int a[], const int& N) {

for(int i = 0 ; i < N ; i++)

cout << "array[" << i << "] = " << a[i] << endl; }

--------------------------------------------------------------------------------------------------------------------------

Create a class called Node: Have a Name and Priority.

Data set - 10 is the highest priority, 1 is lowest priority.

Enqueue and dequeue in the following order.

Function Name, Priority

Enqueue Joe, 3

Enqueue Fred, 1

Enqueue Tuyet, 9

Enqueue Jose, 6

Dequeue

Enqueue Jing, 2

Enqueue Xi, 5

Enqueue Moe, 3

Dequeue

Enqueue Miko, 7

Enqueue Vlady, 8

Enqueue Frank, 9

Enqueue Anny, 3

Dequeue

Enqueue Xi, 2

Enqueue Wali, 2

Enqueue xChe, 6

Enqueue xVerra, 8

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Dequeue

Answer 1

At first, a class called node is created whose data members are name and priority. The object of this class denotes each element of the priority queue. Then a class queue is created which contains the node array of objects. Here the functions like enqueue(), dequeue() and show are defined. After adding each element in the queue, the queue is sorted using quicksort algorithm in ascending order of priority. Finally, the main() contains a menu-driven list of choices and an object of queue class is created to call enqueue(), dequeue() and show() when needed/

Source code:

#include<iostream>
using namespace std;
class node
{
   public:
       string name;
       int priority;
       void input(string n,int p)
       {
           name=n;
           priority=p;
       }
       void display()
       {
           cout<<"\n"<<name<<"\t"<<priority<<endl;
       }
};
void swap(node *a,node *b)
{
   node t;
   t=*a;
   *a=*b;
   *b=t;
}
class queue
{
   public:
       node *a=NULL;
       int size,f,r;
       queue(int n)
       {
           size=n;
           a=new node[size];
           f=r=-1;
       }
       void enqueue()
       {
           string nm;
           int p;
           cout<<"\nEnter name: ";
           cin>>nm;
           cout<<"\nEnter priority: ";
           cin>>p;
           node x;
           x.input(nm,p);
           if(r==size-1)
               cout<<"\nQueue is full"<<endl;
           else if((f==-1)&&(r==-1))
           {
               f=r=0;
               a[r]=x;
           }
           else
           {
               r++;
               a[r]=x;
           }
           quicksort(f,r);
       }
       void quicksort(int l,int r)
       {
           int loc;
           if(l<r)
           {
               loc=pivot(l,r);
               quicksort(l,loc-1);
               quicksort(loc+1,r);
           }
       }
       int pivot(int l,int r)
       {
           int p=a[r].priority;
           node t;
           int i=l-1;
           for(int j=l;j<=r-1;j++)
           {
               if(a[j].priority<p)
               {
                   i++;
                   swap(&a[i],&a[j]);
               }
           }
           swap(&a[i+1],&a[r]);
           return (i+1);
       }
       void dequeue()
       {
           if((f==-1)||(f>r))
               cout<<"\nQueue is empty"<<endl;
           else
           {
               cout<<"Deleted element: ";
               a[f++].display();
           }
       }
       void show()
       {
           if((f==-1)||(f>r))
           {
               cout<<"\nQueue is empty"<<endl;
               return;
           }
           for(int i=f;i<=r;i++)
           {
               a[i].display();
           }
           cout<<endl;
       }
};
int main()
{
   int ch,size;
   cout<<"\nEnter size of queue: ";
   cin>>size;
   queue ob(size);
   while(1)
   {
       cout<<"\nPriority queue operations";
       cout<<"\n1.Enqueue";
       cout<<"\n2.Dequeue";
       cout<<"\n3.Display";
       cout<<"\n4.Exit";
       cout<<"\nEnter your choice: ";
       cin>>ch;
       switch(ch)
       {
           case 1:
           ob.enqueue();
           break;
          
           case 2:
           ob.dequeue();
           break;
          
           case 3:
           ob.show();
           break;
          
           case 4:
           exit(0);
          
           default:
           cout<<"\nInvalid choice.\n";
       }
   }
   return 0;
}

output:

CAUsersUSERDesktop testiqueue.exe nter size of queue 20 riority queue operations Enqueue Dequeue Display Exit nter your choice: 1 nter name Joe nter priority: 3 riority queue operations Enqueue Dequeue Display Exit nter your choice: 1 nter nameFred nter priority: 1 riority queue operations Enqueue Dequeue Display Exit nter your choice: 1 nter name: Tuyet nter priority: 9 riority queue operations Enqueue Dequeue Display Exit nter your choice: 1 nter name Jose nter priority: 6

CAUsers\USER\Desktopltestiqueue.exe Priority queue operations 1. Enqueue 2. Dequeue 3.Display 4.Exit nter your choice: 3 red ое ose 6 uyet riority queue operations 1. Enqueue 2. Dequeue 3.Display 4.Exit Enter your choice: 2 Deleted element: red riority queue operations 1. Enqueue 2. Dequeue 3.Display 4.Exit nter your choice: 1 nter name Jing nter priority: 2 riority queue operations 1. Enqueue 2. Dequeue 3.Display 4.Exit nter your choice: 1 nter name Xi nter piority: 5

CAUsers \USER\Desktopltestiqueue.exe Priority queue operations 1. Enqueue 2. Dequeue Display nter your choice: 1 nter name Moe nter priority: 3 riority queue operations 4.Exit 1. Enqueue 2. Dequeue 3 Display 4.Exit nter your choice: 3 ing ое ое 5 ose 6 uyet riority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 eleted element: ing riority queue operations 1. Enqueue 2. Dequeue Display Exit nter your choice: 1 nter name Miko nter priority:

CAUsersUSERDesktopltestiqueue.exe riority queue operations Enqueue Dequeue Display Exit nter your choice: 1 nter name:Ulady nter priority: 8 riority queue operations 1. Enqueue Dequeue Display Exit nter your choice: 1 nter name Frank nter priority: 9 riority queue operations 1. Enqueue Dequeue Display Exit nter your choice: 1 nter name Anny nter priority: 3 riority queue operations 1. Enqueue Dequeue Display Exit Enter your choice: 2 Deleted element nny

İ CAUsersNUSERNDesktoptestiqueue.exe Priority queue operations 1. Enqueue 2. Dequeue Display 4.Exit nter your choice: 3 ое ое 5 6 2 lady 8 ose iko ranK uyet riority queue operations 1. Enqueue 2. Dequeue Display Exit nter your choice: 1 nter nameR1 nter priority: 2 riority queue operations 1. Enqueue 2. Dequeue Display Exit nter your choice: 1 nter name Wali nter priority: 2

CAUsers USERDesktopltestiqueue.exe Priority queue operations 1.Enqueue 2. Dequeue 3.Display 4. Exit Enter your choice: 1 Enter name: Xche Enter priority: 6 Priority queue operations 1.Enqueue 2. Dequeue 3.Display 4. Exit Enter your choice: 1 Enter name: Xuerra Enter priority: 8 Priority queue operations 1.Enqueue 2. Dequeue 3.Display 4. Exit Enter your choice: 3 Wali Joe Moe Jose Xche Miko 5 6 6 2 verra lady 8 Frank 9 Tuyet 9

Priority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 Deleted element Wali riority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 Deleted element riority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 eleted element: ое riority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 Deleted element ое riority queue operations 1. Enqueue 2. Dequeue Display Exit Enter your choice: 2 Deleted element 5