program conversion.

I have a sequential queue program that was supposed to be a linked queue program.

How do I change it to be correct.

Code:

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#include <iostream.h>

void enqueue (char queue[maxqueue], int& front, int& rear, char item)
        {
  rear=(rear+1)%maxqueue;
  if(front!=rear)
          {
      queue[rear]=item;
      }
  else
          {
      cout<<"OVERFLOW\n";
      rear=rear-1;
      if (rear<0)
              rear=rear+maxqueue;
      };
  };


void dequeue (char queue[maxqueue], int& front, int& rear, char& item)
        {
  if (front!=rear)
          {
      front=(front+1)%maxqueue;
      item=queue[front];
      //queue[front]=' ';
      }
  else
          {
      cout<<"UNDERFLOW--FILLERUP\n";
      item='0';
      };
  };

//lists items on a sequential queue
void list (char queue[maxqueue], int front, int rear)
  {
  int count=0,where;
  //from front to rear and cout
  where=front;
  while (where!=rear)
          {
      where=(where+1)%maxqueue;
      cout<<queue[where];
      count++;
      };
  /*//rearplus=(rear+1)%maxqueue;
  for (where=(front+1)%maxqueue;where!=rearplus;where=(where+1)%maxqueue)
          {
      count++;
      cout<<queue[where];
      }; */
  cout<<endl<<count<<" items on queue"<<endl;
  };

//menu for queue routines
void queuedriver(char queue[maxqueue], int& front, int& rear);

void main ()
{
char answer,table[maxqueue];
int front,rear;

cout<<"We will maintain a queue for you.\n";
cout<<"At your instruction, we will enqueue, dequeue, list, or halt.\n";

do//The whole program as often as needed
{

//initialize counter for task
front=0;
rear=0;

//basic menu driver
queuedriver(table,front,rear);


//allows repeat of whole program
cout<<"Would you like to do another queue simulation('Y' to continue)?\n";
cin>>answer;
}while ((answer=='Y') || (answer=='y'));
};






//menu for queue routines
void queuedriver(char queue[maxqueue], int& front, int& rear)
{
const int maxcommand=4;
char command[maxcommand], thing;


cout<<"the options are as follows:\n";
cout<<"1. enqueue\n";
cout<<"2. dequeue \n";
cout<<"3. list\n";
cout<<"4. halt\n";
do//queue menu options
        {
  cout<<"type command:(en,de,li,ha)\n";
  cin>>command;
  if ((strcmp(command,"enqu")==0) || (strcmp(command,"en")==0) ||
      (strcmp(command,"1")==0)    || (strcmp(command,"e")==0) )
      {
      cout<<"item to put on queue:";
      cin>>thing;
      enqueue(queue,front,rear, thing);
      cout<<thing<<" enqueued on queue \n";
      }
  else if ((strcmp(command,"dequeue")==0) || (strcmp(command,"de")==0) ||
            (strcmp(command,"2")==0)    || (strcmp(command,"d")==0) )
      {
      dequeue(queue,front,rear,thing);
      cout<<thing<<" dequeued from queue\n"<<endl;
      }
  else if  ((strcmp(command,"list")==0) || (strcmp(command,"li")==0) ||
              (strcmp(command,"3")==0)    || (strcmp(command,"l")==0) )
      {
      list(queue,front,rear);
      }
  else if  ((strcmp(command,"halt")==0) || (strcmp(command,"ha")==0) ||
            (strcmp(command,"4")==0)    || (strcmp(command,"h")==0) )
      {
      cout<<"goodbye\n";
      strcpy(command,"h");
      }
  else
          cout<<"unrecognized command\n";

  } while (strcmp(command,"h")!=0);
};

---

Does it compile?

This is outdated.

Code:

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#include <iostream.h>

---

Use <iostream> instead, and either add std:: to all your couts etc or use the namespace.

Code:

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#include <iostream>
using namespace std;

---

Code:

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void main()

---

Don't use this -- use int main() and probably a return 0 statement.

You don't need semicolons after every closing brace after every function.

strcmp() is in <cstring> (or <string.h> if your compiler's really old); be sure to include it.

Code:

---

const int maxcommand=4;
char command[maxcommand], thing;
// ...
  else if ((strcmp(command,"dequeue")==0) || (strcmp(command,"de")==0) ||
            (strcmp(command,"2")==0)    || (strcmp(command,"d")==0) )

---

command[4] can't hold "dequeue". It needs to be at least [8].

My compiler is really old.

Then get a new one:
www.bloodshed.net/devcpp.html

So download a new one. This code won't even compile on some modern compilers. Clicky.