1 files changed, 140 insertions, 0 deletions
diff --git a/test/graph/connect.cpp b/test/graph/connect.cpp
new file mode 100644
index 0000000..bba8104
--- /dev/null
+++ b/test/graph/connect.cpp
@@ -0,0 +1,140 @@
+#include "../util.h"
+#pragma GCC diagnostic ignored "-Wshadow"
+#include "connectMinLCT.h"
+constexpr ll INF = 0x3FFF'FFFF;
+#include <graph/connect.cpp>
+
+struct Naive {
+	vector<multiset<int>> adj;
+	vector<int> seen;
+	int counter;
+	Naive(int n) : adj(n), seen(n), counter(0) {}
+
+	template<typename F>
+	void dfs(int x, F&& f) {
+		counter++;
+		vector<int> todo = {x};
+		seen[x] = counter;
+		while (!todo.empty()) {
+			x = todo.back();
+			todo.pop_back();
+			f(x);
+			for (ll y : adj[x]) {
+				if (seen[y] != counter) {
+					seen[y] = counter;
+					todo.push_back(y);
+				}
+			}
+		}
+	}
+
+	bool connected(int a, int b) {
+		bool res = false;
+		dfs(a, [&](int x){res |= x == b;});
+		return res;
+	}
+
+	void addEdge(int a, int b) {
+		adj[a].insert(b);
+		adj[b].insert(a);
+	}
+
+	void eraseEdge(int a, int b) {
+		adj[a].erase(adj[a].find(b));
+		adj[b].erase(adj[b].find(a));
+	}
+};
+
+void stress_test() {
+	ll queries = 0;
+	for (int tries = 0; tries < 2'000; tries++) {
+		int n = Random::integer<int>(2, 30);
+		int m = Random::integer<int>(30, 300);
+
+		vector<int> insertOrder(m);
+		iota(all(insertOrder), 0);
+		shuffle(all(insertOrder), Random::rng);
+		vector<pair<int, int>> edges(m, {-1, -1});
+
+		connect con(n, m);
+		Naive naive(n);
+
+		int deleted = 0;
+		for (int i = 0; i < m; i++) {
+			{
+				int a = Random::integer<int>(0, n);
+				int b = a;
+				while (b == a) b = Random::integer<int>(0, n);
+				edges[insertOrder[i]] = {a, b};
+
+				con.addEdge(a, b, insertOrder[i]);
+				naive.addEdge(a, b);
+			}
+
+			while (deleted < m && edges[deleted] != pair<int, int>{-1, -1} && Random::integer<int>(2) == 0) {
+				auto [a, b] = edges[deleted];
+
+				con.eraseEdge(deleted);
+				naive.eraseEdge(a, b);
+				deleted++;
+			}
+
+			for (int j = 0; j < n; j++) {
+				int a = Random::integer<int>(0, n);
+				int b = Random::integer<int>(0, n);
+
+				auto got = con.connected(a, b);
+				auto expected = naive.connected(a, b);
+
+				if (got != expected) cerr << "error" << FAIL;
+			}
+
+			queries += n;
+		}
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+
+constexpr int N = 100'000;
+constexpr int M = 500'000;
+void performance_test() {
+	timer t;
+	t.start();
+	connect con(N, M);
+	t.stop();
+
+	vector<int> insertOrder(M);
+	iota(all(insertOrder), 0);
+	shuffle(all(insertOrder), Random::rng);
+	vector<bool> inserted(M);
+
+	for (int i = 0, j = 0; i < N; i++) {
+		int a = Random::integer<int>(0, N);
+		int b = a;
+		while (b == a) b = Random::integer<int>(0, N);
+		
+		t.start();
+		con.addEdge(a, b, insertOrder[i]);
+		t.stop();
+		inserted[i] = true;
+
+		while (j < M && inserted[j] && Random::integer<int>(2) == 0) {
+			t.start();
+			con.eraseEdge(j);
+			t.stop();
+		}
+	}
+	hash_t hash = 0;
+	for (int i = 1; i < N; i++) {
+		t.start();
+		hash += con.connected(i - 1, i);
+		t.stop();
+	}
+	if (t.time > 1000) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test();
+	performance_test();
+}