1-16使用外部变量

#include <stdio.h>

#include <malloc.h>

#define MAXLINE 1000

int max;

char line[MAXLINE];

char longest[MAXLINE];

int getline(void);

void copy(void);

main()

{

int len;

extern int max;

extern char longest[];

max = 0;

while ( (len = getline()) > 0 )

{

if (len > max)

{

max = len;

copy();

}

if (max >0)

printf("%s", longest);

}

return 0;

}

int getline(void)

{

int c, i;

extern char line[MAXLINE];

for (i = 0; (i < MAXLINE -1) && (c = getchar())!=EOF && c != '/n'; ++i)

line[i] = c;

if (c == '/n')

{

line[i] = '/n';

++i;

}

line[i] = '/0';

return i;

}

void copy(void)

{

int i;

extern char line[], longest[];

i = 0;

while((longest[i] = line[i] ) != '/0')

++i;

}