Priority Queue

[RobGillespie]

I'm having trouble wrapping my head around this abstract data type business. I understand how to make a queue and a stack, but this priority queue is throwing me off. I'm supposed to take this header file:

#include "queue-provided.h"

const int PQSIZE = 11;
   
template <class T>
struct PriorityQueue {
   Queue<T> array[PQSIZE];
};
   
void initialize(PriorityQueue<T>&);
void destroy(PriorityQueue<T>&);
 int getSize(PriorityQueue<T>);
bool isEmpty(PriorityQueue<T>);
void push(PriorityQueue<T>&,T,int);
T    pop(PriorityQueue<T>&); 

And make the functions for a priority queue. I'm not sure what to do with how the struct declares a Queue<T> array[PQSIZE]. So basically I'm making an array of queues but i don't know how to push/pop to a queue within the array.

[LB]

"this header file" is not valid C++. So nobody else here knows "what to do with how the".

[RobGillespie]

Sorry, forgot to include the implementation of queue:

#include <iostream>
using namespace std;

const int SIZE = 5;

template <class T>
struct Queue {
   T data[SIZE];
   int tail;
};

template <class T>
void initialize(Queue<T>& Q) {
  Q.tail = 0;
  }

template <class T>
void destroy(Queue<T>& Q) {
  Q.tail = 0;
}

template <class T>
int  getSize(Queue<T> Q) {
  return Q.tail;
}

template <class T>
bool isEmpty(Queue<T> Q) {
  if(Q.tail == 0)
    return true;
  else
    return false;
  }

template <class T>
void push(Queue<T>& Q, T value) {
  Q.data[Q.tail] = value;
  Q.tail++;
}

template <class T>
T pop(Queue<T>& Q) {
  T trash = Q.data[0];
  for(int i = 0; i < Q.tail; i++) {
    Q.data[i] = Q.data[i+1];
  }
  Q.tail--;
  return trash;
}

[RobGillespie]

This is what I'm using to push values into each queue:

template <class T>
void push(PriorityQueue<T>& Q,T value,int rank) {
  push(Q.array[rank], value);
}

Now I can't figure out how to pop the values out of the highest priority queues.

[RobGillespie]

I'm trying this for my pop function, getting the isEmpty function from the header file, but it keeps telling me "no match for operator==" on line 5 below.

template <class T>
T pop(PriorityQueue<T>& Q) {
  int count = PQSIZE;
  while(true) {
      if(isEmpty((Q.array[count]) == true))
         count--;
      else
        break;
  }
  return pop(Q.array[count]);
}

[LB]

Your class is not copyable and you accidently neglected the ampersand in some of your declarations. You need to always pass by reference anyway.