1 files changed, 85 insertions, 0 deletions
diff --git a/test/graph/articulationPoints.cpp b/test/graph/articulationPoints.cpp
new file mode 100644
index 0000000..2567a09
--- /dev/null
+++ b/test/graph/articulationPoints.cpp
@@ -0,0 +1,85 @@
+#include "../util.h"
+struct edge {
+	ll from, to, id;
+};
+#define Edge edge
+#include <graph/articulationPoints.cpp>
+#undef Edge
+
+vector<bool> naiveArt() {
+	vector<bool> res(sz(adj));
+
+	vector<int> seen(sz(adj), -1);
+	for (int i = 0; i < sz(adj); i++) {
+		if (adj[i].empty()) continue;
+		seen[i] = i;
+		vector<ll> todo = {adj[i][0].to};
+		seen[todo[0]] = i;
+		while (!todo.empty()) {
+			int c = todo.back();
+			todo.pop_back();
+			for (auto e : adj[c]) {
+				if (seen[e.to] == i) continue;
+				seen[e.to] = i;
+				todo.push_back(e.to);
+			}
+		}
+		for (auto e : adj[i]) {
+			if (seen[e.to] != i) res[i] = true;
+		}
+	}
+	return res;
+}
+
+void stress_test_art() {
+	ll queries = 0;
+	for (int tries = 0; tries < 200'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(0, max<int>(1, min<int>(300, n*(n-1) / 2 + 1)));
+		Graph<NoData, 0, 1> g(n);
+		g.erdosRenyi(m);
+
+		adj.assign(n, {});
+		int nextId = 0;
+		g.forEdges([&](int a, int b){
+			adj[a].push_back({a, b, nextId});
+			adj[b].push_back({b, a, nextId});
+			nextId++;
+		});
+
+		auto expected = naiveArt();
+		find();
+		vector<bool> got = isArt;
+
+		if (got != expected) cerr << "error" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 500'000;
+constexpr int M = 2'000'000;
+void performance_test() {
+	timer t;
+	Graph<NoData, 0, 1> g(N);
+	g.erdosRenyi(M);
+	adj.assign(N, {});
+	int nextId = 0;
+	g.forEdges([&](int a, int b){
+		adj[a].push_back({a, b, nextId});
+		adj[b].push_back({b, a, nextId});
+		nextId++;
+	});
+
+	t.start();
+	find();	
+	t.stop();
+	hash_t hash = sz(bridges) + sz(bcc);
+	if (t.time > 500) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test_art();
+	performance_test();
+}