1 files changed, 42 insertions, 0 deletions
diff --git a/test/other/josephus2.cpp b/test/other/josephus2.cpp
new file mode 100644
index 0000000..d28fe0d
--- /dev/null
+++ b/test/other/josephus2.cpp
@@ -0,0 +1,42 @@
+#include "../util.h"
+#include <other/josephus2.cpp>
+
+template<ll O>
+ll naive(ll n, ll k) {
+	vector<ll> state(n);
+	iota(all(state), O);
+	for (ll i = k-1; state.size() > 1; i = (i + k - 1) % sz(state)) {
+		state.erase(state.begin() + i);
+	}
+	return state[0];
+}
+
+void stress_test() {
+	ll tests = 0;
+	for (ll i = 1; i < 2'000; i++) {
+		auto got = rotateLeft(i);
+		auto expected = naive<1>(i, 2);
+		if (got != expected) cerr << "error: " << i << FAIL;
+		tests++;
+	}
+	cerr << "tested queries: " << tests << endl;
+}
+
+constexpr int N = 1'000'000'000;
+void performance_test() {
+	timer t;
+	hash_t hash = 0;
+	t.start();
+	for (ll i = 0; i < N; i++) {
+		hash += rotateLeft(1'000'000'000'000'000'000ll + i);
+	}
+	t.stop();
+	if (t.time > 500) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test();
+	performance_test();
+}
+