#include <stdio.h>
#include <stdlib.h>
#include <time.h>
 
int main(void)
{
	int x = -5, y1, y2, z1, z2;
	x = abs(x);   /* returns the absolute value of argument */

	printf(" x = %d\n", x);
		
	printf(" On this computer RAND_MAX = %d\n", RAND_MAX);
	
	y1 = rand();  /* returns a random integer between 0 and RAND_MAX */
	y2 = rand();
	z1 = rand();
	z2 = rand();
	
printf(" y1 = %d\n y2 = %d\n z1 = %d\n z2 = %d\n", y1, y2, z1, z2);
	
	/* Caution: each time when you run this program same random integers will be
	returned. To avoid repetitions you have to seed your random number generator
	with a current time returned by time(NULL) function */
	
	/* seed random generator with current system time */
	x = (int) time(NULL);
	printf("\n current system time = %d\n", x);
	
	srand( x );  
	printf("The random number generator has been reset\n");
	
	/* Now, all generated random integers will be different each time
		you run this program */
	
	y1 = rand();  /* returns a random integer between 0 and RAND_MAX */
	y2 = rand();
	z1 = rand();
	z2 = rand();
	
printf(" y1 = %d\n y2 = %d\n z1 = %d\n z2 = %d\n", y1, y2, z1, z2);
	
return (0);
}