#include<stdio.h>

/* function prints "hello" */
/*declaration */
void print_hello();
/* function prints current year */
void print_current_year();
/* function prints the specific year */
void print_this_year(int y);
/* function tells, if value 1 can be divided by value 2 */
void can_that_be_divided(int v1, int v2);
/* function rounds a decimal value with given decimals, value is printed then */
void round_up_this(double value, int decimals);
/* function rounds a decimal value with given decimals and returns the result */
double round_up_this_and_return(double value, int decimals);

int main()
{
	/* call */
	print_hello();
	print_current_year();
	print_this_year(2020);
	can_that_be_divided(6,3);
	round_up_this(23.45555 ,2);
	double result = round_up_this_and_return(1234.6666,2);
	printf("result is %lf \n",result);
	printf("result is now %lf \n", round_up_this_and_return(8.8888,3));
	double x = 345.678;
	int d = 3;
	print("result is now %lf \n",round_up_this_and_return(x,d));
	return 0;
}

double round_up_this_and_return(double value, int decimals)
{
	int p = 1;
	int k;
	for (k = 0; k < decimals; k++);
	p = p * 10;
	value = (int)(value * p + 0.5)/(1.0*p);
	return value;



}


void round_up_this(double value, int decimals)
{
	int p = 1;
	int k;
	for (k = 0; k < decimals; k++);
	p = p * 10;

	printf("%d \n",p);
	value = (int)(value * p + 0.5)/(1.0*p); /* 23.444 => 2344.4 + 0.5 => 2344.9 */
	printf("result is %lf \n",value);
	/* 23.45555 => 2345.55 => 2346.15 => 2346 => 23.46 */
}

void can_that_be_divided(int v1, int v2)
{
	if (v1%v2 == 0)
	printf("yeah \n");
	else
	printf("nope \n");
}

void print_this_year(int y)
{
	printf("%d \n", y);
}


void print_current_year()
{
	printf("2017 \n");
}


/* definition, implementation */
void print_hello()
{
	printf("hello \n");

}