#include int qwerty_getcode(int code) { return code == 42? 0: 1; } namespace std { void qwerty_exit(int code){ exit(qwerty_getcode(code)); } } using std::qwerty_exit; #define exit qwerty_exit #define main qwerty_main #include "testlib.h" #include using namespace std; using ll = long long; const ll infty = 1e18; ll area(ll x1, ll x2, ll x3, ll y1, ll y2, ll y3) { return (x2 - x1) * (y3 - y1) - (y2 - y1) * (x3 - x1); } int find_optimal_position(int n, const vector& xx, const vector& yy, const vector& alive) { ll mn = infty; int opt = -1; int prev1 = n - 1; while (not alive[prev1]) --prev1; int prev2 = prev1 - 1; while (not alive[prev2]) --prev2; for (int i = 0; i < n; ++i) { if (not alive[i]) continue; ll a = area(xx[prev2], xx[prev1], xx[i], yy[prev2], yy[prev1], yy[i]); if (a < mn) { mn = a; opt = prev1; } prev2 = prev1; prev1 = i; } return opt; } int find_2nd_optimal_position(int n, const vector& xx, const vector& yy, const vector& alive) { ll mn1 = infty, mn2 = infty; int opt1 = -1, opt2 = -1; int prev1 = n - 1; while (not alive[prev1]) --prev1; int prev2 = prev1 - 1; while (not alive[prev2]) --prev2; for (int i = 0; i < n; ++i) { if (not alive[i]) continue; ll a = area(xx[prev2], xx[prev1], xx[i], yy[prev2], yy[prev1], yy[i]); if (a < mn1) { mn2 = mn1; opt2 = opt1; mn1 = a; opt1 = prev1; } else if (a < mn2) { mn2 = a; opt2 = prev1; } prev2 = prev1; prev1 = i; } return opt2; } int find_random_position(int n, const vector& alive) { vector pos; for (int i = 0; i < n; ++i) { if (alive[i]) pos.push_back(i); } int q = pos.size(); return pos[rnd.next(q)]; } int find_position(int n, const vector& xx, const vector& yy, const vector& alive, int strategy) { if (strategy == 0) return find_optimal_position(n, xx, yy, alive); if (strategy == 1) return find_2nd_optimal_position(n, xx, yy, alive); if (strategy == 2) return find_random_position(n, alive); return -1; } ll find_area(int p, int n, const vector& xx, const vector& yy, const vector& alive) { int nxt = (p + 1) % n; while (not alive[nxt]) nxt = (nxt + 1) % n; int prv = (p + n - 1) % n; while (not alive[prv]) prv = (prv + n - 1) % n; return area(xx[prv], xx[p], xx[nxt], yy[prv], yy[p], yy[nxt]); } int main(int argc, char* argv[]) { setName("Greedy Interactor"); registerInteraction(argc, argv); rnd.setSeed(42); int n = inf.readInt(); vector xx(n), yy(n); cout << n << endl; for (int i = 0; i < n; ++i) { xx[i] = inf.readLong(); yy[i] = inf.readLong(); cout << xx[i] << ' ' << yy[i] << endl; } int strategy = 0; // optimal if (n == 44 or n == 45) { strategy = 1; // second optimal } if (n == 78 or n == 79) { strategy = 2; // random } string he = ouf.readToken(); tout << "< " << he << endl; vector alive(n, true); ll our_area = 0, their_area = 0; int cur = n; bool our_turn; if (he == "Alberto") { our_turn = false; } else if (he == "Beatrice") { our_turn = true; } else { quitf(_wa, "unrecognised player name"); } while (cur > 2) { if (our_turn) { int p = find_position(n, xx, yy, alive, strategy); our_area += find_area(p, n, xx, yy, alive); cout << p + 1 << endl; tout << "> " << p + 1 << endl; alive[p] = false; } else { int p = ouf.readInt(1, n, "chosen vertex"); tout << "< " << p << endl; --p; quitif(!alive[p], _wa, "vertex already chosen"); their_area += find_area(p, n, xx, yy, alive); alive[p] = false; } our_turn = !our_turn; --cur; } if (their_area <= our_area) { quitf(_ok, "they win, their_area %lld <= our_area %lld. Used strategy %d", their_area, our_area, strategy); } else { quitf(_wa, "they lose, their_area %lld > our_area %lld. Used strategy %d", their_area, our_area, strategy); } } #undef main #include #include #include #include int main(int argc, char **argv) { namespace fs = std::filesystem; char judge_out[] = "/dev"; std::vector new_argv = { argv[0], argv[1], "/dev/null", argv[2], judge_out, }; return qwerty_getcode(qwerty_main((int)new_argv.size(), new_argv.data())); }