UVa 824 - Coast Tracker

// UVa 824 - Coast Tracker

#include <iostream>
using namespace std;

struct triad {
	int x, y, z;
};

bool wall[8];

int dir[3][3] = { { 3, 2, 1 }, { 4, -1, 0 }, { 5, 6, 7 } };

int to_dir(triad a, triad b) {
	return dir[a.x - b.x + 1][a.y - b.y + 1];
}

int main() {
	triad r;
	while (cin >> r.x >> r.y >> r.z && (r.x != -1)) {
		// read surroundings
		for (int i = 0; i < 8; i++) {
			triad a;
			cin >> a.x >> a.y >> a.z;
			wall[to_dir(a, r)] = (a.z == 0);
		}
		// determine next move
		int d = (r.z + 5) % 8, sol;
		for (int i = 0; i < 8; i++) {
			int dd = (d + i) % 8;
			if (!wall[dd]){
				sol = dd;
				break;
			}
		}
		cout << sol << endl;
	}
	return 0;
}