#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100
int num[MAX],tos=-1;

push(int x)
{
    if(tos==MAX)
    {
        printf("the stack is full");
    }
    else
    {
        printf("  l");
        tos++;
        num[tos]=x;
    }
}
int pop()
{
    if(tos<0)
    {
        printf("stack underflow");
    }
    else
    return num[tos--];
}
int main()
{
    char postfix[MAX],exp[MAX],ch,val;
    int a,b;
    printf("enter the postfix expression");
    fgets(postfix,MAX,stdin);
    strcpy(exp,postfix);
    for(int i=0;i<strlen(postfix);i++)
    {
         printf(" xox ");
        ch=postfix[i];
        if(isdigit(ch))
        {
            push(ch - '0');
            printf(" %d ",atoi(ch));
        }
      else
      {
          printf("%d",tos);
          a=pop();
          b=pop();
          switch(ch)
          {
          case '+':
            val=a+b;
            break;
          case '-':
            val=a-b;
            break;
          case '*':
            val=a*b;
            break;
          case '/':
            val=a/b;
            break;
        }
        printf("%d",val);
        push(val);
      }
    }
    printf("the result of the expression %s = %d",exp,num[0]);
    return 0;
}