#include <iostream>
#include <iomanip>  //for the iomanipulators setw and setprecision
#include <cstdlib>
using namespace std;

int main()
{
	double a[] {     //The values trend upwards, with jiggles.
		10.00,
		11.00,
		10.50,
		12.00,
		11.75,
		12.25,
		12.00,
		12.25,
		12.15,
		12.50,
		12.40,
		12.60

	};
	int n {size(a)};   //the number of elements in the array

	//Tamp down the jiggles by computing the moving average.

	for (int i {2}; i < n - 2; ++i) {
		cout << setw(2) << i << "  "
			<< fixed << setprecision(2)
			<< (a[i-2] + a[i-1] + a[i] + a[i+1] + a[i+2]) / 5.0
			<< "\n";
	}

	cout << "\n";   //Skip a line.

	for (double *p {a+2}; p < a+n-2; ++p) { //a+2 means &a[2]; a+n-2 means &a[n-2]
		cout << setw(2) << p - &a[0] << "  "
			<< fixed << setprecision(2)
			<< (p[-2] + p[-1] + p[0] + p[1] + p[2]) / 5.0 << "\n";
	}

	return EXIT_SUCCESS;
}