#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct {

int top;
char container[20];


}stack ;
int isempty(stack *s)
{
    if(s->top==-1)
    {
        return 1;
    }
    else
        return 0;
}
void push(stack *s,char x)
{
     s->container[++s->top]=x;
       printf("  \n pushed %c at %d \n",x,s->top);

}
char pop (stack *s)
{
    if(isempty(s))
    {
        return 0;
    }
    else
    {
        return (s->container[s->top--]);

    }
}
int getorder(char op)
{
    if(op=='(')
    return 0;
    if(op=='-')
          return 1;
    if(op=='+')
         return 2 ;
    if(op=='*')
        return 4;
    if(op=='/')
        return 3;

}
    int main  (){

    char eqn[]="( 10 + 2.5 ) * 4 + 3";
    char *token;
    char token2[1];
    char neweqn[50]=" ";
    stack *s=malloc(sizeof(stack));
    s->top=-1;
    char *ch1;

    token=strtok (eqn," ");
    while(token!=NULL)
    {
           printf("token now is %c \n",token[0]);

         if(token[0]=='+'||token[0]=='-'||token[0]=='/'||token[0]=='*'||token[0]=='(')
         {

                 printf("operator %c\n",token[0]);

                if(s->top==-1 ||token[0]=='('|| getorder(token[0])>getorder(s->container[s->top]))
             {

                 push(s,token[0]);
             }

             else{

            while(!isempty(s))
            {

            ch1=pop(s);
            if (ch1=='('){break;}
            token2[0]=ch1;
            strcat(neweqn,token2);
            }
            push(s,token[0]);
            }

         }
         else if(!strcmp(token,")"))
         {


           ch1=pop(s);
           printf("popped %c \n",ch1);
             while(ch1!='(')
            {
             token2[0]=ch1;
            strcat(neweqn,token2);
            ch1=pop(s);

            }
         }
         else
        {

            strcat(neweqn,token);

         }




         token=strtok(NULL," ");

    }
    ch1=pop(s);
    token2[0]=ch1;
    strcat(neweqn,token2);
     printf("new eqn .. %s \n",neweqn);
















    }