at the moment this is a stack of queue, i am trying to make it into first in first out, (FIFO) , can anyone help. thank you very much
#include <iostream.h>
#include <stdlib.h>
const int STACK_SIZE = 6;
const int NIL = -1;
const int LAST_ELEMENT = STACK_SIZE - 1;
struct stackType
{
int tos;
char data[STACK_SIZE];
};
void create(stackType&);
bool full(stackType);
bool empty(stackType);
void Push(char, stackType& );
void Pop(char&,stackType& );
void Top( char&, stackType);
void display(stackType);
void create(stackType& s)
{
s.tos = NIL;
}
bool full(stackType s)
{
if(s.tos == LAST_ELEMENT)
return true;
else
return false;
}
bool empty(stackType s)
{
if (s.tos == NIL)
return true;
else
return false;
}
void Push(stackType& s, char achar)
{
s.tos = s.tos + 1;
s.data[s.tos] = achar;
}
void Pop(stackType& s, char& achar)
{
achar = s.data[s.tos];
s.tos = s.tos + 1;
}
void display(stackType s)
{
int i;
for (i = s.tos; i != NIL; i++)
cout << s.data[i] << endl;
}
void Top(stackType s, char& achar)
{
achar = s.data[s.tos];
}
void main()
{
stackType aStack[3];
char command, letter;
int use_stack = 0;
system("cls");
for (int i = 0 ; i<3 ; i++) create(aStack[i]);
cout << "This program uses a stack implemented as an array\n";
cout << "Maximum number of items = " << STACK_SIZE << endl;
do
{
cout << "\nMAKING USE OF STACK " << use_stack;
cout << "\n[P]ush data, P[O]p data, [T]op show top data";
cout << "\n[D]isplay stack, [S]witch stack or [Q]uit -> ";
cin >> command;
switch(command)
{
case 'p' :
case 'P' : if(!full(aStack[use_stack]))
{
cout << "Enter data -> ";
cin >> letter;
Push(aStack[use_stack],letter);
}
else
cout << "The stack is full data not pushed\n";
break;
case 'o' :
case 'O' : if (!empty(aStack[use_stack]))
{
Pop(aStack[use_stack], letter);
cout << letter << " has been popped\n";
}
else
cout << "Stack empty cannot pop\n";
break;
case 't' :
case 'T' : if (!empty(aStack[use_stack]))
{
Top(aStack[use_stack], letter);
cout << letter << " is on top of the stack\n";
cout << "\n";
}
else
cout << "Stack empty cannot pop\n";
break;
case 's' :
case 'S' : do
{
cout << "Which stack do you wish to use (0-2) ";
cin >> use_stack;
} while (use_stack < 0 || use_stack > 2);
break;
case 'd' :
case 'D' : if (!empty(aStack[use_stack]))
display(aStack[use_stack]);
else
cout << "stack empty no data to display\n";
break;
case 'q' :
case 'Q' : cout << "Program terminated\n";
break;
default : cout << "Unknown command [" <<command << "] try again!\n";
break;
}
} while (!(command == 'q' || command == 'Q'));
}
Code tags added. -Narue
