1 files changed, 74 insertions, 0 deletions
diff --git a/test/graph/hopcroftKarp.cpp b/test/graph/hopcroftKarp.cpp
new file mode 100644
index 0000000..05599dd
--- /dev/null
+++ b/test/graph/hopcroftKarp.cpp
@@ -0,0 +1,74 @@
+#include "../util.h"
+namespace kuhn {
+#include <graph/maxCarBiMatch.cpp>
+}
+namespace hk {
+#include <graph/hopcroftKarp.cpp>
+}
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 50'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(0, max<int>(1, n*(n-1) / 2 + 1));
+
+		kuhn::adj.assign(2*n, {});
+		hk::adj.assign(2*n, {});
+
+		Graph<NoData> g(n);
+		g.erdosRenyi(m);
+		g.forEdges([&](int a, int b){
+			kuhn::adj[a].push_back(n+b);
+			kuhn::adj[b+n].push_back(a);
+
+			hk::adj[a].push_back(n+b);
+			hk::adj[b+n].push_back(a);
+		});
+
+		ll got = hk::hopcroft_karp(n);
+		ll expected = kuhn::kuhn(n);
+
+		vector<bool> seen(2*n);
+		ll got2 = 0;
+		for (int i = 0; i < n; i++) {
+			int j = hk::pairs[i];
+			if (j < 0) continue;
+			if (hk::pairs[j] != i) cerr << "error: inconsitent" << FAIL;
+			if (j == i) cerr << "error: invalid" << FAIL;
+			if (j < i) continue;
+			if (seen[i] || seen[j]) cerr << "error: invalid" << FAIL;
+			seen[i] = seen[j] = true;
+			got2++;
+		}
+
+		if (got != got2) cerr << "got: " << got << ", got2: " << got2 << FAIL;
+		if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+//this is an easy graph...
+constexpr int N = 100'000;
+constexpr int M = 500'000;
+void performance_test() {
+	timer t;
+	Graph<NoData> g(N);
+	g.erdosRenyi(M);
+	hk::adj.assign(2*N, {});
+	g.forEdges([&](int a, int b){
+		hk::adj[a].push_back(N+b);
+		hk::adj[b+N].push_back(a);
+	});
+
+	t.start();
+	hash_t hash = hk::hopcroft_karp(N);
+	t.stop();
+	if (t.time > 300) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test();
+	performance_test();
+}