编写程序得出1到100的所有整数出现对少次九

#include <stdio.h>

void fun( int n )
{
int num = 1;
int count = 0;
while( num < 100 )
{
n = num;
while( n!=0 )
{
if( n % 10 == 9 )
count++;
n = n / 10;
}
num++;
}
printf("%d\n",count);
}

int main()
{
fun( 100 );
return 0;
}