Spiraali

#include <bits/stdc++.h>

#define MIN(X, Y) (((X) <  (Y)) ? (X) : (Y))
#define MAX(X, Y) (((X) >= (Y)) ? (X) : (Y))

using namespace std;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n, t, y, x;
	cin >> n >> t;

	while (t--) {
		cin >> y >> x;
		long int r = 1;
		long int cy = 1;
		long int cx = 1;
		int o = 1;
		int f = 1;
		int least = MIN(MIN(x, y), MIN(n + 1 - x, n + 1 - y));
		if (least > 1) {
			while (cx != least && cy != least) {
				cy += (n - o - 1 + f);
				r += (n - o - 1 + f);
				if (!f)
					o++;
				cx += (n - o);
				r += 2*(n - o);
				cy -= (n - o);
				o++;
				f = 0;
				cx -= (n - o);
				r += (n - o);
				cy += 1;
				r += 1;
			}
			//o++;
			f = 0;
		}
		while (1) {
			//cout << "o: " << o << "\n";
			//cout << cy << ", " << cx << "\n";
			// down
			if (cx == x) {
				r += (y - cy);
				break;
			}
			else {
				//cout << "(" << cy << ", " << cx << ") = " << r << "\n";
				//cout << n - o << " down\n";
				cy += (n - o - 1);
				r += (n - o - 1);
				if (f) {
					cy++;
					r++;
				}
			}
			//cout << cy << ", " << cx << "\n";
			// right
			if (cy == y) {
				r += (x - cx);
				break;
			}
			else {
				if (!f)
					o++;
				//cout << "(" << cy << ", " << cx << ") = " << r << "\n";
				//cout << n - o << " right\n";
				cx += (n - o);
				r += (n - o);
			}
			//cout << cy << ", " << cx << "\n";
			// up
			if (cx == x) {
				r += (cy - y);
				break;
			}
			else {
				//cout << "(" << cy << ", " << cx << ") = " << r << "\n";
				//cout << n - o << " up\n";
				cy -= (n - o);
				r += (n - o);
			}
			//cout << cy << ", " << cx << "\n";
			// left
			if (cy == y) {
				r += (cx - x);
				break;
			}
			else {
				o++;
				f = 0;
				//cout << "(" << cy << ", " << cx << ") = " << r << "\n";
				//cout << n - o << " left\n";
				cx -= (n - o);
				r += (n - o);
			}
		}
		cout << r << "\n";
	}

	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: TIME LIMIT EXCEEDED