#include <math.h>
#include <algorithm>
#include <functional>
#include <vector>
#include <iostream>

using namespace std;

const double PI = 3.1415926535897932384626433832795;

struct circle {

	double radius;
	char code;

	circle()
		: radius(0.0)
		, code(' ') {
	}

	circle(double x, double y, char c) {

		radius = sqrt(x*x + y*y);
		code = c;
	}

	bool operator < (const circle& c) const {
		
		return radius < c.radius;
	}

	bool operator > (const circle& c) const {
		
		return !(*this < c);
	}

	double length() const {
		
		return radius * PI * 2;
	}
};

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

	vector<circle> v(3);

	v[0] = circle(5.6,   2.3,  'A');
	v[1] = circle(-10.1, 4.7,  'B');
	v[2] = circle(7.4,  -12.3, 'C');

	sort(v.begin(), v.end(), greater<circle>());

	for(vector<circle>::iterator iter = v.begin();
		iter != v.end();
		++iter)
		cout << "Circle: " << iter->code << ", length: " << iter->length() << endl;

  	return	0;
}