#include <iostream.h>
#include <math.h>
#include <iomanip.h>
#include <stdlib.h>
#include <fstream.h>
#include <string>
#include <process.h>
#include<stdio.h>

void main()
{
    //program d12r7
    //driver for routine correl
	int n,n2,i,j;
	double data1[65],data2[65],ans[129],cmp;
    n = 64;
    n2 = 128;
    const double pi = 3.1415926;  
	for(i=0; i<=128; i++)
	{
		ans[i]=0.0;
	}
    for (i = 1; i<=n; i++)
	{
        data1[i] = 0.0;
        if (i>(n / 2 - n / 8) && i <(n / 2 + n / 8))
		{
            data1[i] = 1.0;
        }
		data2[i]=data1[i];
    }
    correl(data1,data2,n,ans);
    cout<<endl;
    cout<<"   n         correl     direct calc"<<endl;
    for (i = 0; i<=16; i++)
	{
        cmp = 0.0;
        for( j = 1; j<=n; j++)
		{
            cmp = cmp + data1[((i + j - 1)%n) + 1] * data2[j];
        }
		cout<<setprecision(0)<<setw(4)<<i;
        cout<<setprecision(6)<<setw(16)<<ans[i + 1];
        cout<<setprecision(6)<<setw(10)<<cmp<<endl;
	}
}