Calculator

#include<stdio.h>
#include<stdlib.h>
#define SIZE 50

struct stack
{
  private: int head; int A[SIZE];
  public: stack()
          {
              head=0;
          }
          int top(void){
                return A[head];
          }
          int limit(void){
                return head;
          }
          void push(int data)
          {
              A[head++]=data;
          }
          int pop()
          {
              return A[--head];
          }
          bool is_full()
          {
              if(head==SIZE) return true;
              else return false;
          }
          bool is_empty()
          {
              if(head == 0) return true;
              else return false;
          }
};

int main(int argc, char *argv[]){
    stack s,s1;
    char line[100];
    int i=0,hold;
    printf("Enter The Arithmetic Expression : ");
    gets(line);
    while(line[i]!='\0'){
        if(line[i]>='0' && line[i]<='9') s.push(line[i]-48);
        else if(line[i]=='+' || line[i]=='-' || line[i]=='*' || line[i]=='/'){
            switch(line[i]){
                case '+':
                s.push(s.pop()+s.pop());
                break;
                case '-':
                s.push(s.pop()-s.pop());
                break;
                case '*':
                s.push(s.pop()*s.pop());
                break;
                case '/':
                hold = s.pop();
                s.push(s.pop()/hold);
                break;
            }

        }
        i++;
    }
    printf("%d",s.pop());
    return 0;
}