CSES - Datatähti 2022 alku - Results
Submission details
Task:Spiraali
Sender:mbezirgan
Submission time:2021-10-14 19:57:21 +0300
Language:C++ (C++17)
Status:READY
Result:35
Feedback
groupverdictscore
#1ACCEPTED15
#2ACCEPTED20
#30
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1details
#2ACCEPTED0.01 s2details
#30.01 s3details

Code

#include <iostream>
#include <cmath>

struct ULong2
{
	uint64_t x, y;
};

uint64_t GetSpiralValue(uint64_t size, const ULong2& pos)
{
	// Distance form center for each axis
	ULong2 distance =
	{
		pos.x >= size / 2 ? pos.x - size / 2 : size / 2 - pos.x - 1,
		pos.y >= size / 2 ? pos.y - size / 2 : size / 2 - pos.y - 1
	};
	// Maximum distance from the center tells witch ring it is.
	// Maybe can be optimized, but no.
	uint64_t ringFromCenter = std::max(distance.x, distance.y);
	uint64_t ringInToCenter = (ringFromCenter <= size / 2 ? size / 2 - ringFromCenter : (size / 2 + 1) - ringFromCenter) - 1;

	// Can be optimized as its a linear sum (I think).
	uint64_t ringStartPoint = 1 + size * size - std::pow(2 * ringFromCenter + 2, 2);

	ULong2 RelativePos =
	{
		pos.x - ringInToCenter,
		pos.y - ringInToCenter,
	};

	if (RelativePos.x == 0 && RelativePos.y == 0)
		return ringStartPoint;
	if (RelativePos.x == 0)
		return ringStartPoint + RelativePos.y;
	if (RelativePos.y == 2 * ringFromCenter + 1)
		return ringStartPoint + RelativePos.x + 2 * ringFromCenter + 1;
	if (RelativePos.x == 2 * ringFromCenter + 1)
		return ringStartPoint - RelativePos.y + 2*(2 * ringFromCenter + 2) + (2 * ringFromCenter) - 1;
	if (RelativePos.y == 0)
		return ringStartPoint - RelativePos.x + 2 * (2 * ringFromCenter + 2) + 2 * (2 * ringFromCenter);

	return 0;
}

int main()
{
	int n, t;
	std::cin >> n;
	std::cin >> t;
	
	ULong2* positions = new ULong2[t];

	for (int i = 0; i < t; i++)
	{
		uint64_t x, y;
		std::cin >> x;
		std::cin >> y;

		positions[i] = { y - 1, x - 1 };
	}

	for (int i = 0; i < t; i++)
	{
		auto& pos = positions[i];

		std::cout << GetSpiralValue(n, pos) << "\n";
	}

	delete[] positions;
	//for (int y = 0; y < n; y++)
	//{
	//	for (int x = 0; x < n; x++)
	//	{
	//		std::cout << GetSpiralValue(n, { (uint64_t)x, (uint64_t)y }) << " ";
	//	}
	//	std::cout << "\n";
	//}
}

Test details

Test 1

Group: 1

Verdict: ACCEPTED

input
10 100
1 1
1 2
1 3
1 4
...

correct output
1
36
35
34
33
...

user output
1
36
35
34
33
...
Truncated

Test 2

Group: 2

Verdict: ACCEPTED

input
1000 1000
371 263
915 322
946 880
53 738
...

correct output
773533
312166
206053
200080
593922
...

user output
773533
312166
206053
200080
593922
...
Truncated

Test 3

Group: 3

Verdict:

input
1000000000 1000
177757853 827347032
409613589 419171337
739269360 256524697
328695530 896842209
...

correct output
571375684522141210
967321186816598569
762879105851175000
370065046779516790
936897883750373771
...

user output
571375684522141209
967321186816598632
762879105851174999
370065046779516793
93689788375037
...
Truncated