#include <stdio.h>

void hello(int n);

double dprod(double *x, int n);

void dcumsum(double *a, double *b, int n);

void
hello(int n)
{
    int i;
    
    for (i = 0; i < n; i++)
    {
        printf("C says hello\n");
    }
}


double 
dprod(double *x, int n)
{
    int i;
    double y = 1.0;
    
    for (i = 0; i < n; i++)
    {
        y *= x[i];
    }

    return y;
}

void
dcumsum(double *a, double *b, int n)
{
    int i;
    
    b[0] = a[0];
    for (i = 1; i < n; i++)
    {
        b[i] = a[i] + b[i-1];
    }
}