1 files changed, 76 insertions, 0 deletions
diff --git a/test/math/longestIncreasingSubsequence.cpp b/test/math/longestIncreasingSubsequence.cpp
new file mode 100644
index 0000000..407dafe
--- /dev/null
+++ b/test/math/longestIncreasingSubsequence.cpp
@@ -0,0 +1,76 @@
+#include "../util.h"
+constexpr ll INF = LL::INF;
+#include <math/longestIncreasingSubsequence.cpp>
+#define lis unstrictLis
+#define lower_bound upper_bound
+#include <math/longestIncreasingSubsequence.cpp>
+#undef lower_bound
+#undef lis
+
+template<bool STRICT>
+bool isLis(const vector<ll>& a, const vector<int>& lis) {
+	for (int i = 1; i < sz(lis); i++) {
+		if (lis[i-1] >= lis[i]) return false;
+		if (a[lis[i-1]] > a[lis[i]]) return false;
+		if (STRICT && a[lis[i-1]] == a[lis[i]]) return false;
+	}
+	return true;
+}
+
+template<bool STRICT>
+vector<int> naive(const vector<ll>& a) {
+	vector<int> res;
+	for (ll i = 1; i < (1ll << sz(a)); i++) {
+		vector<int> tmp;
+		for (ll j = 0; j < sz(a); j++) {
+			if (((i >> j) & 1) != 0) tmp.push_back(j);
+		}
+		if (sz(tmp) >= sz(res) && isLis<STRICT>(a, tmp)) res = tmp;
+	}
+	return res;
+}
+
+void stress_test() {
+	ll queries = 0;
+	for (ll i = 0; i < 10'000; i++) {
+		int n = Random::integer<int>(1, 12);
+		auto a = Random::integers<ll>(n, -10, 10);
+		auto expected = naive<true>(a);
+		auto got = lis(a);
+		if (got != expected) cerr << "error: strict" << FAIL;
+		queries += n;
+	}
+	for (ll i = 0; i < 10'000; i++) {
+		int n = Random::integer<int>(1, 12);
+		auto a = Random::integers<ll>(n, -10, 10);
+		auto expected = naive<false>(a);
+		auto got = unstrictLis(a);
+		if (got != expected) cerr << "error: not strict" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 1'000'000;
+void performance_test() {
+	timer t;
+	auto a = Random::integers<ll>(N, -10'000, 10'000);
+	auto b = Random::integers<ll>(N, -10'000, 10'000);
+	sort(all(b));
+	auto c = Random::integers<ll>(N, -10'000, 10'000);
+	sort(all(c));
+	reverse(all(c));
+	hash_t hash = 0;
+	t.start();
+	hash += lis(a).size();
+	hash += lis(b).size();
+	hash += lis(c).size();
+	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();
+}