1 files changed, 65 insertions, 0 deletions
diff --git a/test/graph/havelHakimi.cpp b/test/graph/havelHakimi.cpp
new file mode 100644
index 0000000..71476ec
--- /dev/null
+++ b/test/graph/havelHakimi.cpp
@@ -0,0 +1,65 @@
+#include "../util.h"
+#include <graph/havelHakimi.cpp>
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 200'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(0, n*(n-1) / 2 + 1);
+		Graph g(n);
+		g.erdosRenyi(m);
+
+		vector<int> expected(n);
+		for (int i = 0; i < n; i++) expected[i] = g.deg(i);
+
+		auto res = havelHakimi(expected);
+		if (sz(res) != n) cerr << "error: wrong number of nodes" << FAIL;
+		vector<vector<int>> rev(n);
+		vector<int> got(n);
+		for (int i = 0; i < n; i++) {
+			got[i] = sz(res[i]);
+			for (int j : res[i]) {
+				if (j < 0 || j >= n) cerr << "error: invalid edge" << FAIL;
+				rev[j].push_back(i);
+			}
+		}
+
+		for (int i = 0; i < n; i++) {
+			sort(all(res[i]));
+			sort(all(rev[i]));
+			if (res[i] != rev[i]) cerr << "error: graph is directed" << FAIL;
+			for (int j : res[i]) if (j == i) cerr << "error: graph has loop" << FAIL;
+			for (int j = 1; j < sz(res[i]); j++) {
+				if (res[i][j] == res[i][j-1]) cerr << "error: multiedge" << FAIL;
+			}
+		}
+
+		if (expected != got) cerr << "error" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 200'000;
+constexpr int M = 1'000'000;
+void performance_test() {
+	timer t;
+	Graph g(N);
+	g.erdosRenyi(M);
+
+	vector<int> expected(N);
+	for (int i = 0; i < N; i++) expected[i] = g.deg(i);
+
+	t.start();
+	auto res = havelHakimi(expected);
+	t.stop();
+	hash_t hash = 0;
+	for (auto& v : res) hash += sz(v);
+	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();
+}