P66

#include<stdio.h>
char fun(char ch)
{
	if(ch>='0'&&ch<='9')
		return '9'-(ch-'0');
}
main()
{
	char c1,c2;
	printf("\nThe result:\n");
	c1='2';c2=fun(c1);
	printf("c1=%c c2=%c\n",c1,c2);
	c1='8';c2=fun(c1);
	printf("c1=%c c2=%c\n",c1,c2);
	c1='a';c2=fun(c1);
	printf("c1=%c c2=%c\n",c1,c2);
}

P66