mzuenni tests

1 files changed, 64 insertions, 0 deletions

diff --git a/test/graph/articulationPoints.bridges.cpp b/test/graph/articulationPoints.bridges.cpp
new file mode 100644
index 0000000..a1b89d2
--- /dev/null
+++ b/test/graph/articulationPoints.bridges.cpp
@@ -0,0 +1,64 @@
+#include "../util.h"
+struct edge {
+	ll from, to, id;
+};
+#define Edge edge
+#include <graph/articulationPoints.cpp>
+#undef Edge
+
+vector<bool> naiveBridges(const vector<pair<int, int>>& edges) {
+	vector<bool> res(sz(edges));
+
+	vector<int> seen(sz(adj), -1);
+	for (int i = 0; i < sz(edges); i++) {
+		auto [a, b] = edges[i];
+		vector<int> todo = {a};
+		seen[a] = i;
+		while (!todo.empty() && seen[b] != i) {
+			int c = todo.back();
+			todo.pop_back();
+			for (auto e : adj[c]) {
+				if (e.id == i) continue;
+				if (seen[e.to] == i) continue;
+				seen[e.to] = i;
+				todo.push_back(e.to);
+			}
+		}
+		res[i] = seen[b] != i;
+	}
+	return res;
+}
+
+void stress_test_bridges() {
+	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, {});
+		vector<pair<int, int>> edges;
+		g.forEdges([&](int a, int b){
+			adj[a].push_back({a, b, sz(edges)});
+			adj[b].push_back({b, a, sz(edges)});
+			edges.emplace_back(a, b);
+		});
+
+		auto expected = naiveBridges(edges);
+		find();
+		vector<bool> got(sz(edges));
+		for (auto e : bridges) {
+			if (got[e.id]) cerr << "error: duclicate" << FAIL;
+			got[e.id] = true;
+		}
+
+		if (got != expected) cerr << "error" << FAIL;
+		queries += n;
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+int main() {
+	stress_test_bridges();
+}