K and R C, Solution to Exercise 4-11:
K and R C Programs Exercises provides the solution to all the exercises in the C Programming Language (2nd Edition). You can learn and solve K&R C Programs Exercise.
C Program to modify the K & R C Programs Exercise 4-3, Modify the gettop function so that it doesn’t need to use ungetch by using internal static variable. Read more about C Programming Language .

/***********************************************************
* You can use all the programs on  www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact info@c-program-example.com
* To find more C programs, do visit www.c-program-example.com
* and browse!
* 
*                      Happy Coding
***********************************************************/

#include<stdio.h>
#include<ctype.h>
#define NUMBER '0'

int getch(void);

/* getop: get next operator or numeric operand. */
int getop(char s[])
{
 int i ;
 int c;
 static int lastc = 0;

 if(lastc == 0)
  c = getch();
 else{
  c = lastc;
  lastc = 0;
 }

 while((s[0] = c) == ' ' || c == 't')
  c = getch();
 s[1] = '