#include <stdio.h>

#define MAXLINE 1000    /* maximum input line size */

/* external variables */
int max;                /* maximum length seen so far */
char line[MAXLINE];     /* current input line */
char longest[MAXLINE];  /* longest line saved here */

int getline(void);
void copy(void);

/* print longest input line; specialized version */
main()
{
   int len;
   extern int max;
   extern char longest[];

   max = 0;
   while ((len = getline()) > 0)
       if (len > max) {
           max = len;
           copy();
       }
   if (max > 0)  /* there was a line */
       printf("%s", longest);
   return 0;
}

/* getline:  specialized version */
int getline(void)
{
   int c, i;
   extern char line[];

   for (i = 0; i < MAXLINE - 1 
        && (c=getchar()) != EOF && c != '\n'; ++i)
            line[i] = c;
   if (c == '\n') {
       line[i] = c;
       ++i;
   }
   line[i] = '\0';
   return i;
}

/* copy: specialized version */
void copy(void)
{
   int i;
   extern char line[], longest[];

   i = 0;
   while ((longest[i] = line[i]) != '\0')
       ++i;
}

/*
Discuss:

- local vs. global/external variables
- local = automatic (created & disappear as function called/exited)
- external variables: defined exactly once outside of any functions,
                      declared in functions that want to use
- splitting into files, header files


*/