CSES - DatatÃ¤hti 2022 alku - Results
 Task: Spiraali (Spiral) Sender: mbezirgan Submission time: 2021-10-14 19:58:05 Language: C++17 Status: READY Result: 100
Feedback
groupverdictscore
#1ACCEPTED15
#2ACCEPTED20
#3ACCEPTED65
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1details
#2ACCEPTED0.01 s2details
#3ACCEPTED0.01 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 - (2 * ringFromCenter + 2)*(2 * ringFromCenter + 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
...

#### 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
...

#### Test 3

Group: 3

Verdict: ACCEPTED

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

correct output
571375684522141210
967321186816598569
762879105851175000
370065046779516790
936897883750373771
...

user output
571375684522141210
967321186816598569
762879105851175000
370065046779516790
936897883750373771
...