// interactor.cpp // Build: g++ -std=gnu++17 -O2 -pipe -static -s interactor.cpp -o interactor // Run : interactor [--seed=...] // input: one line "n s" // Protocol: // - Player output: walk x (0 <= x <= 1e9) -- Interactor responds: label[pos] // - Player output: guess g -- Terminates; if g==n then score by q, otherwise score 0 // // Rules: // - Initial: label[s]=s, used set = {s} // - When walking to position pos that hasn't been assigned: repeatedly random r in [1..n] until r not in used, then label[pos]=r, add r to used // - Maximum walk count MAX_Q=200000 // // Scoring: f(q) is log10 space piecewise linear interpolation: // (1,100), (10000,95), (20000,60), (50000,30), extrapolated to 0 at 200000 // Correct: quitp(f/100), wrong: quitp(0) #include "testlib.h" #include using namespace std; static const long long MAX_Q = 200000LL; // Continuous, monotonically decreasing, log10 piecewise linear interpolation static double score_from_queries(long long q) { if (q <= 1) return 100.0; const double t = log10((double)q); const double t1 = 0.0; // log10(1) const double t2 = 4.0; // log10(10000) const double t3 = log10(20000.0); // ~4.30103 const double t4 = log10(50000.0); // ~4.69897 const double t5 = log10(200000.0); // ~5.30103 auto lerp = [](double a, double b, double x, double xa, double xb) { if (xa == xb) return a; double w = (x - xa) / (xb - xa); return a + (b - a) * w; }; if (t <= t2) return lerp(100.0, 95.0, t, t1, t2); else if (t <= t3) return lerp(95.0, 60.0, t, t2, t3); else if (t <= t4) return lerp(60.0, 30.0, t, t3, t4); else if (t <= t5) return max(0.0, lerp(30.0, 0.0, t, t4, t5)); else return 0.0; } int main(int argc, char* argv[]) { registerInteraction(argc, argv); // Read n, s long long n = inf.readLong(1LL, 1000000000LL, "n"); long long s = inf.readLong(1LL, n, "s"); long long pos = s; long long qcnt = 0; // Node -> visible value; assigned only on first visit to node unordered_map label; label.reserve(1 << 16); label.max_load_factor(0.7f); // Set of used numbers to avoid duplicates unordered_set used; used.reserve(1 << 16); used.max_load_factor(0.7f); // Initialize label[s] = s; used.insert(s); // Sample an unused random number (n is large, expected attempts is low) auto take_random_unused_number = [&]() -> long long { while (true) { long long r = rnd.next(1LL, n); if (!used.count(r)) { used.insert(r); return r; } } }; auto tell = [&](long long v) { cout << v << '\n' << flush; }; while (true) { string cmd = ouf.readWord(); // Read a word (non-whitespace characters) if (cmd == "walk") { long long x = ouf.readLong(0LL, 1000000000LL, "x"); // cerr< MAX_Q) { quitf(_wa, "Too many queries: %lld (max %lld)", qcnt, MAX_Q); } tell(label[pos]); } else if (cmd == "guess") { long long g = ouf.readLong(1LL, 1000000000LL, "n_guess"); bool ok = (g == n); if (!ok) { quitp(0.0, "Wrong answer. hidden n=%lld, your guess=%lld, queries=%lld", n, g, qcnt); } else { double score = score_from_queries(qcnt); double part = max(0.0, min(100.0, score)) / 100.0; double unbounded_part = max(0.0, score) / 100.0; quitp(part, "OK. n=%lld, queries=%lld, Ratio: %.4f, RatioUnbounded: %.4f", n, qcnt, part, unbounded_part); } } else { quitf(_wa, "Unknown command: '%s' (expected 'walk' or 'guess')", cmd.c_str()); } } }