1 files changed, 67 insertions, 0 deletions
diff --git a/graph/test/binary_lifting.cpp b/graph/test/binary_lifting.cpp
new file mode 100644
index 0000000..05b903a
--- /dev/null
+++ b/graph/test/binary_lifting.cpp
@@ -0,0 +1,67 @@
+#include "util.cpp"
+#include "../binary_lifting.cpp"
+
+void test(vector<vector<int>> &adj, int root) {
+	int n = adj.size();
+
+	vector<int> parent(n);
+	function<void(int,int)> dfs = [&](int u, int p) {
+		parent[u] = p;
+		for (int v: adj[u]) if (v != p) dfs(v, u);
+	};
+	dfs(root, -1);
+
+	function<bool(int, int)> is_ancestor = [&](int u, int v) {
+		while (v != -1 && u != v) v = parent[v];
+		return u == v;
+	};
+	function<int(int)> depth = [&](int v) {
+		int r = 0;
+		while ((v = parent[v]) != -1) r++;
+		return r;
+	};
+
+	Lift lift(adj, root);
+	for (int i = 0; i < n; i++) assert(lift.depth(i) == depth(i));
+	for (int i = 0; i < 1000; i++) {
+		int v = util::randint(n);
+		int d = util::randint(n);
+		int u = lift.lift(v, d);
+		assert(is_ancestor(u, v));
+		if (d <= depth(v)) assert(depth(u) == d);
+		else assert(u == v);
+	}
+	for (int i = 0; i < 1000; i++) {
+		int u = util::randint(n);
+		int v = util::randint(n);
+		int lca = lift.lca(u, v);
+		assert(is_ancestor(lca, u));
+		assert(is_ancestor(lca, v));
+		for (int p = parent[lca]; int c: adj[lca]) {
+			if (c == p) continue;
+			assert(!is_ancestor(c, u) || !is_ancestor(c, v));
+		}
+	}
+}
+
+int main() {
+	{
+		// Single vertex
+		vector<vector<int>> adj(1);
+		test(adj, 0);
+	}
+	{
+		// Path
+		vector<vector<int>> adj = util::path(100);
+		int left = 0, mid = 40, right = 99;
+		util::shuffle_graph(adj, left, mid, right);
+		test(adj, left);
+		test(adj, mid);
+		test(adj, right);
+	}
+	{
+		// Random
+		vector<vector<int>> adj = util::random_tree(1000);
+		test(adj, 0);
+	}
+}