i need help to rewrite this in infix to postfix using class. it was in a struct format at first, now i need to format this in a class version.
#include <iostream>
#include <cstring>
using namespace std;
const int SIZE = 20;
private: int top;
char num [SIZE];
public: void stack_init (stack_type&);
void push (stack_type& , char);
void pop (stack_type&, char& );
int is_empty ( stack_type&);
int is_full (stack_type&);
}
int main ()
{
char infix [20], postfix [20]="", ch;
int size, i, j=-1;
stack_type stack;
stack_init (stack);
cout << "Enter an infix string with no embedded blanks";
cin >> infix;
size = strlen(infix);
for ( i = 0; i < size ; i++ )
{
if (infix [i] == '+' || infix [i] == '-' ||
infix [i] == '*' || infix [i] == '/' )
// if current char is an operator *************
if ( infix [i] == '+' || infix [i] == '-')
{ if (!is_empty(stack))
{pop (stack, ch);
while (ch=='+'|| ch=='-'||ch=='*'||ch=='/')
{ j++;
postfix [j] = ch;
ch = ' '; // blank out ch for later testing
if (!is_empty(stack))
pop (stack, ch);
}
if (ch != ' ')
push (stack, ch );
push (stack,infix[i]);
}
else // if stack is empty
push (stack, infix[i]);
}
else // if current operand is a high prec operand
{ if (!is_empty(stack))
{pop (stack, ch);
while (ch=='*'||ch=='/')
{ j++;
postfix [j] = ch;
ch = ' '; // blank out ch for later testing
if (!is_empty(stack))
pop (stack, ch);
}
if (ch != ' ')
push (stack, ch );
push (stack,infix[i]);
}
else // if stack is empty
push (stack, infix[i]);
}
else // current char is operand or parenthesis
if (infix[i] == '(')
push (stack, infix[i]);
else
if (infix[i] == ')')
{pop (stack,ch);
while (ch != '(')
{ j++;
postfix[j] = ch;
pop (stack,ch);
}
}
else // current is an operand
{j++;
postfix[j] = infix[i];
}
} // end of for i loop
while (!is_empty(stack))
{j++;
pop (stack,ch);
postfix[j] = ch;
}
cout << postfix << endl;
return 0;
}
void stack_init (stack_type& s )
{ s.top = -1;
}
void push (stack_type& s, char item)
{
if (s.top+1 < SIZE)
{ s.top ++;
s.num [s.top] = item;
}
}
void pop (stack_type & s , char& item )
{ if (s.top > -1 )
{ item = s.num[s.top];
s.top --;
}
}
int is_empty ( stack_type& s )
{ if (s.top > -1 )
return 0;
else
return 1;
}
int is_full (stack_type& s )
{ if (s.top == SIZE-1)
return 1;
else
return 0;
}Code tags added. -Narue
