// printf, scanf, etc.
#include <stdio.h> 

// rand, srand
#include <stdlib.h>

// time functions
#include <time.h>

// pi, sin, cos, exp
#include <math.h>

int get_int()
{
	int val;
	// note: you pass in the address
	scanf("%d", &val);
	printf("you typed %d\n",val);
	return val;
}

int get_rand()
{
	int x = rand();
	return x%10;
}

int main()
{
	// call scanf
	int junk = get_int();

	// set random seed
	srand(time(NULL));
	//srand(2);

	int x = get_rand();
	printf("x = %d\n", x);
	int y = get_rand();
	printf("y = %d\n", y);

	// do math
	float a = 12.0f, b = 55.0f, e = 2.7182818f;

	printf("cos(a) = %f\n", M_PI);//cos(a));
	printf("sqrt(b) = %f\n", sqrt(b));
	printf("log(e) = %f\n", log(M_E));

	return 0;
}