1 files changed, 43 insertions, 0 deletions
diff --git a/content/graph/articulationPoints.cpp b/content/graph/articulationPoints.cpp
new file mode 100644
index 0000000..25ff67e
--- /dev/null
+++ b/content/graph/articulationPoints.cpp
@@ -0,0 +1,43 @@
+vector<vector<Edge>> adj;
+vector<int> num;
+int counter, rootCount, root;
+vector<bool> isArt;
+vector<Edge> bridges, st;
+vector<vector<Edge>> bcc;
+
+int dfs(int v, int from = -1) {
+	int me = num[v] = ++counter, top = me;
+	for (Edge& e : adj[v]) {
+		if (e.id == from) continue;
+		if (num[e.to]) {
+			top = min(top, num[e.to]);
+			if (num[e.to] < me) st.push_back(e);
+		} else {
+			if (v == root) rootCount++;
+			int si = sz(st);
+			int up = dfs(e.to, e.id);
+			top = min(top, up);
+			if (up >= me) isArt[v] = true;
+			if (up > me) bridges.push_back(e);
+			if (up <= me) st.push_back(e);
+			if (up == me) {
+				bcc.emplace_back(si + all(st));
+				st.resize(si);
+	}}}
+	return top;
+}
+
+void find() {
+	counter = 0;
+	num.assign(sz(adj), 0);
+	isArt.assign(sz(adj), false);
+	bridges.clear();
+	st.clear();
+	bcc.clear();
+	for (int v = 0; v < sz(adj); v++) {
+		if (!num[v]) {
+			root = v;
+			rootCount = 0;
+			dfs(v);
+			isArt[v] = rootCount > 1;
+}}}