Submission #59928

#	Time	Username	Problem	Language	Result	Execution time	Memory
59928		Eae02	Circle selection (APIO18_circle_selection)	C++14	19 / 100	3066 ms	37644 KiB

circle_selection

#include <bits/stdc++.h>
#define ALL(x) x.begin(),x.end()

struct Circle
{
	int64_t x;
	int64_t y;
	int64_t r;
	int64_t i;
	int64_t elimBy;
	
	int64_t minX() const
	{
		return x - r;
	}
	int64_t maxX() const
	{
		return x + r;
	}
};

int main()
{
	int num;
	std::cin >> num;
	std::vector<Circle> circles(num);
	std::vector<Circle*> cByMin(num);
	std::vector<Circle*> cByMax(num);
	
	bool allZeroY = true;
	
	for (int i = 0; i < num; i++)
	{
		std::cin >> circles[i].x;
		std::cin >> circles[i].y;
		std::cin >> circles[i].r;
		circles[i].i = i;
		circles[i].elimBy = -1;
		cByMin[i] = &circles[i];
		cByMax[i] = &circles[i];
		
		if (circles[i].y != 0)
			allZeroY = false;
	}
	
	std::sort(ALL(circles), [&] (const Circle& a, const Circle& b)
	{
		if (a.r == b.r)
			return a.i < b.i;
		return a.r > b.r;
	});
	
	if (allZeroY)
	{
		std::sort(ALL(cByMin), [&] (const Circle* a, const Circle* b)
		{
			return a->minX() < b->minX();
		});
		
		std::sort(ALL(cByMax), [&] (const Circle* a, const Circle* b)
		{
			return a->maxX() < b->maxX();
		});
		
		for (Circle& outer : circles)
		{
			if (outer.elimBy != -1)
				continue;
			outer.elimBy = outer.i;
			
			auto minB = std::lower_bound(ALL(cByMin), outer.minX(), [&] (Circle* c, int64_t pos) { return c->minX() < pos; });
			auto minE = std::upper_bound(ALL(cByMin), outer.maxX(), [&] (int64_t pos, Circle* c) { return pos < c->minX(); });
			
			auto maxB = std::lower_bound(ALL(cByMax), outer.minX(), [&] (Circle* c, int64_t pos) { return c->maxX() < pos; });
			auto maxE = std::upper_bound(ALL(cByMax), outer.maxX(), [&] (int64_t pos, Circle* c) { return pos <= c->maxX(); });
			
			std::for_each(minB, minE, [&] (Circle* c)
			{
				if (c->elimBy == -1)
					c->elimBy = outer.i;
			});
			std::for_each(maxB, maxE, [&] (Circle* c)
			{
				if (c->elimBy == -1)
					c->elimBy = outer.i;
			});
		}
	}
	else
	{
		for (Circle& outer : circles)
		{
			if (outer.elimBy != -1)
				continue;
			outer.elimBy = outer.i;
			for (Circle& inner : circles)
			{
				if (inner.elimBy != -1)
					continue;
				int64_t dx = inner.x - outer.x;
				int64_t dy = inner.y - outer.y;
				int64_t rSum = inner.r + outer.r;
				if (dx * dx + dy * dy <= rSum * rSum)
					inner.elimBy = outer.i;
			}
		}
	}
	
	std::vector<int64_t> result(num);
	for (int i = 0; i < num; i++)
		result[circles[i].i] = circles[i].elimBy + 1;
	for (int i = 0; i < num; i++)
		std::cout << result[i] << " ";
	std::cout << std::endl;
}

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 30
• Subtask 6: 0 / 13