c++ program with code

#include<iostream>

#include<cctype>

using namespace std;

class evalPostFix

{

public:

int s[50];

int top;

char str[50];

evalPostFix() {

top=-1;

}

void push(int val) {

top++;

s[top]=val;

}

int pop() {

int val=s[top];

top--;

return val;

}

int oper(int x,int y,char op) {

switch(op) {

case '+':return x+y;

case '-':return x-y;

case '*':return x*y;

case '/':return x/y;

default: return 0;

}

}

int calc();

};

int evalPostFix::calc()

{

int i=0; int j = 0;

while(str[j]!='$')

{

if (isalpha(str[j]))

{

cout<<"Enter the value of "<<str[j];

cin>> str[j];

}

j++;

}

while(str[i]!='$') {

if(isdigit(str[i])) {

push(str[i]-'0');

}

else {

int x=pop();

int y=pop();

int r=oper(x,y,str[i]);

push(r);

}

i++;

}

return pop();

}

int main()

{

char answer;

evalPostFix eval;

do

{

cout<<"Enter a postfix expression with a $ at the end:" << endl;

cin>>eval.str;

int r=eval.calc();

cout<<"Final Value : "<<r <<"\n";

cout << "Continue (Y or N)?" << endl;

cin >> answer;

}

while(answer!='N');

system("pause");

}

Here is the output, but I do not want it to be like this.

I want the output to be like this