Thread: how do I turn this int into a float

I need to put use the stacks for floats instead of integers but I tried turning every thing from int to float but it did not work. Here is my code. Any help will be appreciated.

Code:

#include <stdio.h>
#include <iostream.h>
#include <stdlib.h>

class STACK
{
private:
  int S[100];//stack
  int Ssize;//stack size

public:
  STACK();//constructor
  void push(int c);//push char onto stack
  int pop(); //remove char from the stack
  int size(); // returns the number of items on the stack
  bool full(); // true if stack is full
};

STACK::STACK()
{
  Ssize =0;
}
void STACK::push(int c)
{
  if (Ssize != 100)
    S[Ssize++]=c;
  else
    cout<<"***Stack overflow-program terminated..."<<endl;
 }

 int STACK::pop()
 {
   return S[--Ssize];
 }

 bool STACK::full()
 {
   if (Ssize==100)
     return true;
   else
     return false;
  }

  int STACK::size()
  {
    return Ssize;
  }


void main(void)
{
  int a,b,end;

  int i;
  char M[]="(((4+8)/4)*(9-7));";

  STACK V,O;
  i=0;
  while (M[i]!=';')
  {
    if (M[i]==')')
    {
      b=V.pop();
      a=V.pop();
      switch (O.pop())
      {
      case 0:
        V.push(a+b);
        break;
      case 1:
        V.push(a-b);
        break;
      case 2:
        V.push(a*b);
        break;
      case 3:
        V.push(a/b);
        break;
      }
    }
    else
      switch(M[i])
      {
        case'0':
          V.push(0);
          break;

        case'1':
          V.push(1);
          break;

        case'2':
          V.push(2);
          break;

        case'3':
          V.push(3);
          break;

        case'4':
          V.push(4);
          break;

        case'5':
          V.push(5);
          break;

        case'6':
          V.push(5);
          break;

        case'7':
          V.push(7);
          break;

        case'8':
          V.push(8);
          break;

        case'9':
          V.push(9);
          break;

        case'+':
          O.push(0);
          break;

        case'-':
          O.push(1);
          break;

        case'*':
          O.push(2);
          break;

        case'/':
          O.push(3);
          break;
    }
    i++;
}
cout<<V.pop()<<endl;
cin>>end;
  return 0;
}

If you change everything to float you will indeed have a problem. You are "switching" on the popped value of your stack. You cannot switch on a floating point number. You will have to do something differetly. You can use a binary tree for your expressions if you want.

Well, you could do:

float a;
switch((int)a){

or:

float a;
int i = (int)a;
switch(i){

I tried changing that but now it acts like it is trapped in a loop.
Here is my code now.

Code:

#include <stdio.h>
#include <iostream.h>
#include <stdlib.h>

class STACK
{
private:
  int S[100];//stack
  int Ssize;//stack size

public:
  STACK();//constructor
  void push(int c);//push char onto stack
  int pop(); //remove char from the stack
  int size(); // returns the number of items on the stack
  bool full(); // true if stack is full
};

STACK::STACK()
{
  Ssize =0;
}
void STACK::push(int c)
{
  if (Ssize != 100)
    S[Ssize++]=c;
  else
    cout<<"***Stack overflow-program terminated..."<<endl;
 }

 int STACK::pop()
 {
   return S[--Ssize];
 }

 bool STACK::full()
 {
   if (Ssize==100)
     return true;
   else
     return false;
  }

  int STACK::size()
  {
    return Ssize;
  }


void main(void)
{
  int a,b;

  int i,end;
  char M[]="(((4+8)/4)*(9-7));";

  STACK V,O;
  i=0;
  while (M[i]!=';')
  {
    if (M[i]==')')
    {
      b=V.pop();
      a=V.pop();
      switch (O.pop())
      {
      case 0:
        V.push(a+b);
        break;
      case 1:
        V.push(a-b);
        break;
      case 2:
        V.push(a*b);
        break;
      case 3:
        V.push(a/b);
        break;
      }
    }
    else
      float a;
      int i = (int)a;
      switch(i){

     // switch(M[i])
      //{
        case'0':
          V.push(0.0);
          break;

        case'1':
          V.push(1.1);
          break;

        case'2':
          V.push(2.1);
          break;

        case'3':
          V.push(3.1);
          break;

        case'4':
          V.push(4.1);
          break;

        case'5':
          V.push(5.1);
          break;

        case'6':
          V.push(6.1);
          break;

        case'7':
          V.push(7.1);
          break;

        case'8':
          V.push(8.1);
          break;

        case'9':
          V.push(9.1);
          break;

        case'+':
          O.push(0);
          break;

        case'-':
          O.push(1);
          break;

        case'*':
          O.push(2);
          break;

        case'/':
          O.push(3);
          break;
    }
    i++;
}
cout<<V.pop()<<endl;
cin>>end;
  return 0;
}

Hey, just a thought, but I thought that stacks are supposed to be dynamically-allocated, instead of having a fixed array?

(i.e. the array starts out with 0 elements or something, then when you Push() a new object on, it resizes to 1 element, and when you Push() another on, it resizes to 2 elements, etc.)

Ok, never mind it's not really important, just an idea if you ever decide to expand on the stack class.