struct BALL
{
	char color ;
	int radius ;
	int counter;
	int counter2;
}; 


float *a;
unsigned long *b;
unsigned char *c;

int counter_data;

int main
{

//read data
for (int k=0;k<100;k++)
{
...
...
...
	ball[k].counter2 = counter_data;
	if (ball[k].counter2 != ball[k].counter)
	{
		ball[k].counter2 = ball[k].counter;
		if (a!=NULL)
		{
			free(a);
			a=NULL;
		}
		if (b!=NULL)
		{
			free(b);
			a=NULL;
		}
		if (c!=NULL)
		{
			free(c);
			a=NULL;
		}
		a=malloc(ball[k].counter2*sizeof(a));
		b=malloc(ball[k].counter2*sizeof(b));
		c=malloc((int)ceil(ball[k].counter2/8.0)*sizeof(c)); 
		/*
		a=malloc(ball[k].counter2*sizeof(float));
		b=malloc(ball[k].counter2*sizeof(unsigned long))
		c=malloc((int)ceil(ball[k].counter2/8.0)*sizeof(unsigned char) );
		*/
	}

}
..
...
...


// write data
...

for (int j=0;j<100;j++)
{
...
...
...
	ball[j].counter2 = counter_data;
	if (ball[j].counter2 != ball[j].counter)
	{
		ball[j].counter2 = ball[j].countea;
		if (a!=NULL)
		{
			free(a);
			a=NULL;
		}
		if (b!=NULL)
		{
			free(b);
			a=NULL;
		}
		if (c!=NULL)
		{
			free(c);
			a=NULL;
		}
		a=malloc(ball[j].counter2*sizeof(a));
		b=malloc(ball[j].counter2*sizeof(b));
		c=malloc((int)ceil(ball[j].counter2/8.0)*sizeof(c)); 
		/*
		a=malloc(ball[j].counter2*sizeof(float));
		b=malloc(ball[j].counter2*sizeof(unsigned long))
		c=malloc((int)ceil(ball[j].counter2/8.0)*sizeof(unsigned char) );
		*/
	}

}

}