1 files changed, 68 insertions, 0 deletions
diff --git a/test/graph/minCostMaxFlow.cpp b/test/graph/minCostMaxFlow.cpp
new file mode 100644
index 0000000..8c92aa7
--- /dev/null
+++ b/test/graph/minCostMaxFlow.cpp
@@ -0,0 +1,68 @@
+#include "../util.h"
+#pragma GCC diagnostic ignored "-Wshadow"
+namespace matching {
+	constexpr int N_LEFT = 1000;
+	constexpr int N_RIGHT = 1000;
+	constexpr double INF = LD::INF;
+	#include <graph/maxWeightBipartiteMatching.cpp>
+}
+namespace mcmf {
+	#include <graph/minCostMaxFlow.cpp>
+}
+
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 20'000; tries++) {
+		auto [l, r] = Random::pair<int>(1, 30);
+		mcmf::MinCostFlow mcmf(l+r+2, 0, 1);
+
+		for (int i = 0; i < l; i++) mcmf.addEdge(0, 2 + i, 1, 0);
+		for (int i = 0; i < r; i++) mcmf.addEdge(2 + l + i, 1, 1, 0);
+		for (int i = 0; i < l; i++) {
+			for (int j = 0; j < r; j++) {
+				matching::costs[i][j] = Random::integer<int>(-100, 100);
+				mcmf.addEdge(2 + i, 2 + l + j, 1, -matching::costs[i][j]);
+			}
+		}
+
+		mcmf.mincostflow();
+		ll got = -mcmf.mincost;
+		double expected = matching::match(l, r);
+
+		if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		queries += l + r;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 1'000;
+constexpr int M = 10'000;
+void performance_test() {
+	using namespace mcmf;
+	timer t;
+
+	Graph<NoData> g(N);
+	g.erdosRenyi(M);
+	MinCostFlow mcmf(N, 0, 1);
+	vector<ll> potential = Random::integers<ll>(N, 0, 1'000'000ll);
+	g.forEdges([&](int a, int b){
+		ll c = Random::integer<ll>(1, 1000'000);
+		ll cost = Random::integer<ll>(0, 1000'000);
+		mcmf.addEdge(a, b, c, potential[b] + cost - potential[a]);
+		mcmf.addEdge(b, a, c, potential[a] + cost - potential[b]);
+	});
+
+	t.start();
+	mcmf.mincostflow();
+	t.stop();
+
+	hash_t hash = mcmf.mincost;
+	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();
+}