uva_1338_distant galaxy

#include<iostream>      
#include<sstream>      
#include<string>      
#include<vector>      
#include<list>      
#include<set>      
#include<map>    
#include<stack>      
#include<queue>      
#include<algorithm>      
#include<numeric>      
#include<cmath>    
#include<cstdio>    
#include<cstdlib>    
#include<cstring>    
#pragma warning(disable:4996)   
using namespace std;
class Point
{
public:
	int x, y;
	friend bool operator<(const Point& a, const Point& b)
	{
		if (a.x != b.x)
		{
			return a.x < b.x;
		}
		return a.y < b.y;
	}
};
int getAns(const vector<Point>&coordinate, vector<int>&coordinate_y)
{
	int ans = 0;
	for (size_t i = 0; i < coordinate_y.size(); i++)
	{
		for (size_t j = i + 1; j < coordinate_y.size(); j++)
		{
			int y_min = coordinate_y[i], y_max = coordinate_y[j], line = -1;
			vector<int>left(coordinate.size()), on1(coordinate.size()), on2(coordinate.size());
			for (int k = 0; k < coordinate.size(); k++)
			{
				if (!k || coordinate[k].x != coordinate[k - 1].x)
				{
					line++;
					if (line)
					{
						left[line] = left[line - 1] + on2[line - 1] - on1[line - 1];
					}
				}
				if (coordinate[k].y > y_min && coordinate[k].y < y_max)
				{
					on1[line]++;
				}
				if (coordinate[k].y >= y_min && coordinate[k].y <= y_max)
				{
					on2[line]++;
				}
			}
			int increment = 0;
			for (int t = 0; t <= line; t++)
			{
				ans = max(ans, left[t] + on2[t] + increment);
				increment = max(increment, on1[t] - left[t]);
			}
		}
	}
	return ans;
}

int main()
{
	//freopen("input.txt", "r", stdin);    
	//freopen("output.txt", "w", stdout);
	int n, cas = 1;
	while (cin >> n && n)
	{
		//接收数据&离散化
		vector<Point>coordinate(n);
		vector<int>coordinate_y(n);
		map<int, int>discrete_x, discrete_y;
		for (int i = 0; i < n; i++)
		{
			cin >> coordinate[i].x >> coordinate[i].y;
			discrete_x.insert({ coordinate[i].x,0 });
			discrete_y.insert({ coordinate[i].y,0 });
		}
		int count = 0;
		for (auto iter = discrete_x.begin(); iter != discrete_x.end(); iter++)
		{
			iter->second = count++;
		}
		count = 0;
		for (auto iter = discrete_y.begin(); iter != discrete_y.end(); iter++)
		{
			iter->second = count++;
		}
		for (int i = 0; i < n; i++)
		{
			coordinate[i].x = discrete_x[coordinate[i].x];
			coordinate_y[i] = coordinate[i].y = discrete_y[coordinate[i].y];
		}
		if (discrete_x.size() <= 2 || discrete_y.size() <= 2)
		{
			printf("Case %d: %d\n", cas++, n);
			continue;
		}
		sort(coordinate.begin(), coordinate.end());
		sort(coordinate_y.begin(), coordinate_y.end());
		auto iter = unique(coordinate_y.begin(), coordinate_y.end());
		coordinate_y.resize(iter - coordinate_y.begin());
		printf("Case %d: %d\n", cas++, getAns(coordinate, coordinate_y));
	}
	return 0;
}