// This program seeds the random-number generator
// with the time, then exercises the rand function.
//

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

void SimpleRandDemo( int n )
{
 // Print n random numbers.
 int i;
 for( i = 0; i < n; i++ )
 printf( " %6d\n", rand() );
}

void RangedRandDemo( int range_min, int range_max, int n )
{
 // Generate random numbers in the half-closed interval
 // [range_min, range_max). In other words,
 // range_min <= random number < range_max
 int i;
 for ( i = 0; i < n; i++ )
 {
 int u = (double)rand() / (RAND_MAX + 1) * (range_max - range_min)
 + range_min;
 printf( " %6d\n", u);
 }
}

int main( void )
{
 // Seed the random-number generator with the current time so that
 // the numbers will be different every time we run.
 srand( (unsigned)time( NULL ) );

 SimpleRandDemo( 10 );
 printf("\n");
 RangedRandDemo( -100, 100, 10 );
}