1 files changed, 41 insertions, 0 deletions
diff --git a/test/string/z.cpp b/test/string/z.cpp
new file mode 100644
index 0000000..f890a3e
--- /dev/null
+++ b/test/string/z.cpp
@@ -0,0 +1,41 @@
+#include "../util.h"
+#include <string/z.cpp>
+
+vector<int> naive(const string& s) {
+	vector<int> res(sz(s));
+	for (int i = 1; i < sz(s); i++) {
+		while (i + res[i] < sz(s) && s[res[i]] == s[i + res[i]]) res[i]++;
+	}
+	return res;
+}
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 15);
+		auto s = Random::string(n, "abc");
+		auto got = Z(s);
+		auto expected = naive(s);
+		if (got != expected) cerr << "error" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 10'000'000;
+void performance_test() {
+	timer t;
+	auto s = Random::string(N, "a") + Random::string(N, "ab") + Random::string(N, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789$#");
+	t.start();
+	auto res = Z(s);
+	t.stop();
+	hash_t hash = 0;
+	for (int x : res) hash += x;
+	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();
+}