Spiraali

#include <iostream>

using namespace std;

typedef long long ull;

ull hae(ull n, ull y, ull x)
{
    ull vasen = x;
    ull ala = n - y + 1;
    ull oikea = n - x + 1;
    ull yla = y;

    ull r = min(vasen, min(ala, min(oikea, yla)));

    // cout << "r " << r << "\n";

    // ull tulos = (ull)((r - 1) * ((-4 * (2 * 1 - n - 1) - 4 * (2 * (r - 1) - n - 1)) / 2));
    ull tulos = (-4 * (r - 1) * ((r - 1) - n));

    if (r == vasen)
    {
        tulos = (tulos + (y - r + 1));
        return tulos;
    }

    tulos = (tulos + n - 2 * (r - 1));

    if (r == ala)
    {
        tulos = tulos + (x - r);
        return tulos;
    }

    tulos = (tulos + n - 2 * (r - 1));

    if (r == oikea)
    {
        // cout << "Korkeus " << (n - 2 * (r - 1)) << "    (y - r) " << (y - r + 1) << "\n";
        tulos = (tulos + (n - 2 * (r - 1)) - (y - r + 1) - 1);
        return tulos;
    }

    tulos = (tulos + n - 2 * (r - 1));

    if (r == yla)
    {
        tulos = (tulos + (n - 2 * (r - 1)) - (x - r + 1) - 2);
        return tulos;
    }

    return tulos;
}

int main()
{
    ull n, t;
    cin >> n >> t;

    for (int i = 0; i < t; i++)
    {
        ull y, x;
        cin >> y >> x;
        cout << hae(n, y, x) << "\n";
    }
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED