Chocolate Chip Cookies/허준수

~cpp
#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

struct Cookies {
	double x;
	double y;
	int numCookies;
};

vector<Cookies> cookies;

void input(double x, double y)
{
	Cookies cooki;
	cooki.x = x;
	cooki.y = y;
	cooki.numCookies = 0;
	cookies.push_back(cooki);
}

void process()
{
	double d;
	int i,j;
	for(i = 0; i<cookies.size()-1; i++) {
		for(j = i+1; j<cookies.size(); j++) {
			d = sqrt(pow(cookies[i].x - cookies[j].x, 2) + pow(cookies[i].y - cookies[j].y , 2));
			if(d <= 5.0) {
				cookies[i].numCookies++;
				cookies[j].numCookies++;
			}

		}
	}
	
	int max_num = 0;
	for(i=0; i<cookies.size(); i++) {
		if(cookies[i].numCookies > max_num)
			max_num = cookies[i].numCookies;
	}

	cout << max_num <<endl;

	cookies.clear();
}

int main()
{
	double x, y;
	int testCase;
	cin >> testCase;
	while(testCase>0) {
		cout << endl;
		while(true)
		{
			cin.ignore();
			if(cin.peek() == '\n')
				break;
			else
				cin >> x >> y;
			input(x,y);
		}
		process();
		testCase--;
	}

	return 0;
}