通过递归调用把整数转换成字符

#include <stdio.h>

#define MAXLINE 100

#define is_other 1

#define is_digital 2

//通过递归调用把整数转换成字符;

void printd(int n) 

{
if (n < 0)
{
putchar('-');
n = - n ;
}
if (n > 0)
{
printd(n / 10);
putchar(n % 10 + '0');
}

}

void copy(char to[] , char from[])

{
int i;
i = 0;
while ((to[i]=from[i]) != '\0')
++i;

}

int main(void)

{

char getline[MAXLINE];
char done[MAXLINE];
int i , c , state , id;
   i = 0;
while((c = getchar())!= '#')
{
getline[i++] = c;
if (getline[i] >= '0' && getline[i] <= '9')
{
state = is_digital;
id = getline[i]; 
printd(id);
}
else if((getline[i] >= 'A' && getline[i] <= 'Z') || (getline[i] >= 'a' && getline[i] <= 'z'))
{
state =is_other;
copy(done ,getline);
printf("%s",done);
}
}

return 0;

}