main.cc
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	/* -------------------------------------------------------------------------- */
	#include <cstdlib>
	#include <cmath>
	#include <iostream>
	#include <iomanip>
	/* -------------------------------------------------------------------------- */

	int main(int argc, char ** argv){

	int precision = 20;

	// Number of iterations
	int n;
	int nmax = 1e7;
	if (argc > 1) {
	n = atoi(argv[1]);
	if (n > nmax) {
	std::cout << "\033[31m" << "Warning: n = " <<
	n << " is too high -> setting n = " << nmax <<
	"\033[0m" << std::endl;
	n = nmax;
	}
	} else {
	n = 10;
	}

	// Normal Pi computation
	float sum = 0;
	for (float k = 1; k < n + 1; k++){
	sum = sum + 1 / (k * k);
	// std::cout<< std::fixed << std::setprecision(precision)
	// << "k = " << k << ", PI = " << sqrt(6 * sum) << std::endl;
	}
	float pi = sqrt(6 * sum);
	std::cout<< std::fixed << std::setprecision(precision)
	<< n << " iterations (normal): PI = " << pi << std::endl;

	// Reversed Pi computation
	sum = 0;
	for (float k = n; k > 0; k--){
	sum = sum + 1/(k*k);
	// std::cout<< std::fixed << std::setprecision(precision)
	// << "k = " << k << ", PI = " << sqrt(6 * sum) << std::endl;
	}
	float rev_pi = sqrt(6 * sum);
	std::cout<< std::fixed << std::setprecision(precision)
	<< n << " iterations (reversed): PI = " << rev_pi << std::endl;

	std::string str;
	if (abs(pi - M_PI) < abs(rev_pi - M_PI)) {
	str = "normal";
	} else {
	str = "reversed";
	}
	std::cout << str << " computation is more accurate" << std::endl;

	return EXIT_SUCCESS;
	}