merge mzuenni changes

1 files changed, 83 insertions, 0 deletions

diff --git a/test/graph/hld.cpp b/test/graph/hld.cpp
new file mode 100644
index 0000000..bcd9c8c
--- /dev/null
+++ b/test/graph/hld.cpp
@@ -0,0 +1,83 @@
+#include "../util.h"
+#include <graph/hld.cpp>
+
+struct Seg { // very real segment tree
+    vector<int> a;
+
+    Seg(int n) : a(n) {}
+    
+    void inc(int l, int r) {
+        for (int i=l; i<r; i++) a[i]++;
+    }
+};
+
+void stress_test() {
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 50);
+		Graph<NoData> g(n);
+		g.tree();
+
+        adj.assign(n, {});
+		g.forEdges([&](int a, int b){
+			adj[a].push_back(b);
+			adj[b].push_back(a);
+		});
+
+        init(Random::integer(0, n));
+
+        vector<int> a(n);
+        auto dfs = [&](auto& self, int u, int p, int t) {
+            if (u == t) {
+                a[u]++;
+                return true;
+            }
+            for (int v : adj[u]) if (v != p) {
+                if (self(self, v, u, t)) {
+                    a[u]++;
+                    return true;
+                }
+            }
+            return false;
+        };
+
+        Seg seg(n);
+
+        int Q = Random::integer(1, 50);
+        for (int q=0; q<Q; q++) {
+            int u = Random::integer(0, n), v = Random::integer(0, n);
+            for_intervals(u, v, [&](int l, int r) { seg.inc(l, r); });
+            dfs(dfs, u, -1, v);
+        }
+        for (int i=0; i<n; i++) {
+            if (seg.a[in[i]] != a[i]) cerr << "WA: expected " << a[i] << " got " << seg.a[in[i]] << FAIL;
+        }
+	}
+	cerr << "tested random tests: " << 100'000 << endl;
+}
+
+constexpr int N = 1'000'000;
+void performance_test() {
+	timer t;
+	Graph<NoData> g(N);
+	g.tree();
+    adj.assign(N, {});
+	g.forEdges([&](int a, int b){
+		adj[a].push_back(b);
+		adj[b].push_back(a);
+	});
+    vector<pair<int, int>> qu(N);
+    for (auto& [x, y] : qu) x = Random::integer(0, N), y = Random::integer(0, N);
+
+    ll hash = 0;
+	t.start();
+    init(0);
+    for (auto [x, y] : qu) for_intervals(x, y, [&](int l, int r){ hash += r-l; });
+	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();
+}