1 files changed, 90 insertions, 0 deletions
diff --git a/test/graph/floydWarshall.cpp b/test/graph/floydWarshall.cpp
new file mode 100644
index 0000000..a93a9ea
--- /dev/null
+++ b/test/graph/floydWarshall.cpp
@@ -0,0 +1,90 @@
+#include "../util.h"
+constexpr ll INF = LL::INF;
+struct edge {
+	int from, to;
+	ll cost;
+};
+#include <graph/bellmannFord.cpp>
+namespace floydWarshall {
+#include <graph/floydWarshall.cpp>
+}
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(2, 30);
+		int m = Random::integer<int>(n-1, max<int>(n, min<int>(500, n*(n-1) / 2 + 1)));
+		vector<ll> potential = Random::integers<ll>(n, 0, 1'000'000'000'000ll);
+
+		vector<edge> edges;
+		floydWarshall::dist.assign(n, vector<ll>(n, INF));
+		for (int i = 0; i < n; i++) floydWarshall::dist[i][i] = 0;
+
+		Graph<NoData, true> g(n);
+		g.erdosRenyi(m);
+		g.forEdges([&](int a, int b){
+			ll w = Random::integer<ll>(1, 100'000'000'000ll);
+			w = potential[b] + w - potential[a];
+			edges.push_back({a, b, w});
+			floydWarshall::dist[a][b] = min(floydWarshall::dist[a][b], w);
+		});
+
+		vector<vector<ll>> orig = floydWarshall::dist;
+
+		floydWarshall::floydWarshall();
+		for (int i = 0; i < n; i++) {
+			for (int j = 0; j < 10; j++) {
+				int k = Random::integer<int>(0, n);
+				auto path = floydWarshall::getPath(i, k);
+				if (path.empty() != (floydWarshall::dist[i][k] == INF)) cerr << "error: reconstruction" << FAIL;
+				if (path.empty()) continue;
+				if (path.front() != i) cerr << "error: start" << FAIL;
+				if (path.back() != k) cerr << "error: end" << FAIL;
+				for (int l = 1; l < sz(path); l++) {
+					if (floydWarshall::dist[i][path[l-1]] +
+						orig[path[l-1]][path[l]] +
+						floydWarshall::dist[path[l]][k] !=
+						floydWarshall::dist[i][k]) cerr << "error: edge" << FAIL;
+				}
+			}
+		}
+
+		for (int i = 0; i < n; i++) {
+			auto got = floydWarshall::dist[i];
+			auto expected = bellmannFord(n, edges, i);
+			
+			if (got != expected) cerr << "error" << FAIL;
+			queries += n;
+		}
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 500;
+constexpr int M = 20'000;
+void performance_test() {
+	timer t;
+	Graph<NoData> g(N);
+	g.erdosRenyi(M);
+	floydWarshall::dist.assign(N, vector<ll>(N, INF));
+	for (int i = 0; i < N; i++) floydWarshall::dist[i][i] = 0;
+	g.forEdges([&](int a, int b){
+		ll w1 = Random::integer<ll>(1, 1'000'000'000'000ll);
+		ll w2 = Random::integer<ll>(1, 1'000'000'000'000ll);
+		floydWarshall::dist[a][b] = w1;
+		floydWarshall::dist[b][a] = w2;
+	});
+
+	t.start();
+	floydWarshall::floydWarshall();
+	t.stop();
+	hash_t hash = 0;
+	for (auto x : floydWarshall::dist[42]) 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();
+}