# include <stdio.h>

double dran01 ( int *seed );

int main ( )
{
  double dot;
  int i;
  int seed = 123456789;
//
//  X and Y are vectors.  We don't know about these yet!
//
  double x[10];
  double y[10];
//
//  Fill X and Y with random values.
//  In C, the 10 entries of vector X are X[0], X[1], ... X[9]!
//
  for ( i = 0; i < 10; i++ )
  {
    x[i] = dran01 ( &seed );
    y[i] = dran01 ( &seed );
  }
//
//  The dot product of two vectors is the sum of their pairwise products.
//
  dot = 0.0;
  for ( i = 0; i < 10; i++ )
  {
    dot = dot + x[i] * y[i];
  }
  printf ( "\n" );
  printf ( "The dot product is %g\n", dot );

  return 0;
}