10920 - Spiral Tap

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    ll sz, p;
    while (cin >> sz >> p, sz || p) {
        ll x, y;
        x = y = (sz + 1) / 2;
        auto calc = [&](ll rot) {
            return 1 + 2 * rot * rot + 2 * (rot + 1) * (rot);
        };
        auto BS = [&]() {
            ll l = 0, r = 1;
            while (calc(r) <= p) r *= 2;
            ll best = 0;
            while (l <= r) { // 111111111100000000000
                ll mid = l + (r - l) / 2;
                (calc(mid) <= p ? l = mid + 1, best = mid : r = mid - 1);
            }
            return best;
        };
        int rot = BS();
        y -= rot;
        x += rot;

        ll sum = calc(rot);
        if (sum < p) {
            int con = rot * 2 + 1;
            vector<ll> nums = {con, con, con + 1, con + 1};
            int i = 0;
            for (i = 0; i < 4 && sum + nums[i] <= p; i++) {
                sum += nums[i];
                if (i == 0) y += nums[i];
                if (i == 1) x -= nums[i];
                if (i == 2) y -= nums[i];
                if (i == 3) x += nums[i];
            }
            if (sum < p) {
                if (i == 0) y += p - sum;
                if (i == 1) x -= p - sum;
                if (i == 2) y -= p - sum;
                if (i == 3) x += p - sum;
            }
        }
        cout << "Line = " << y << ", column = " << x << ".\n";
    }
}