add remaining tests

5 files changed, 251 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();
+}
diff --git a/test/graph/reroot.cpp b/test/graph/reroot.cpp
new file mode 100644
index 0000000..d5043b4
--- /dev/null
+++ b/test/graph/reroot.cpp
@@ -0,0 +1,59 @@
+#include "../util.h"
+#include <graph/reroot.cpp>
+
+void stress_test() {
+	for (int tries = 0; tries < 50'000; 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].emplace_back(b, Random::integer(0, 10));
+			adj[b].emplace_back(a, Random::integer(0, 10));
+		});
+
+        Reroot re;
+        auto ans = re.solve();
+
+        auto dfs = [&](auto& self, int u, int p) -> ll {
+            ll val = 0;
+            for (auto [v, w] : adj[u]) if (v != p) {
+                val ^= ((v ^ u) + self(self, v, u)) * w % MOD;
+            }
+            return u ^ val;
+        };
+        for (int i=0; i<n; i++) {
+            if (ans[i] != dfs(dfs, i, -1)) {
+                cerr << "WA expected " << dfs(dfs, i, -1) << " got " << ans[i] << FAIL;
+            }
+        }
+	}
+	cerr << "tested random 50'000 tests" << 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].emplace_back(b, Random::integer(0, (int)1e9));
+        adj[b].emplace_back(a, Random::integer(0, (int)1e9));
+	});
+
+    ll hash = 0;
+	t.start();
+    Reroot re;
+    auto ans = re.solve();
+    hash = accumulate(all(ans), 0LL);
+	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();
+}
diff --git a/test/graph/reroot.cpp.awk b/test/graph/reroot.cpp.awk
new file mode 100644
index 0000000..37ce8c3
--- /dev/null
+++ b/test/graph/reroot.cpp.awk
@@ -0,0 +1,7 @@
+BEGIN { print "constexpr ll MOD = 1e9 + 7;" }
+{ 
+    sub("W w, T x) {\\}", "W w, T x) { return ((v ^ c) + x) * w % MOD; }")
+    sub("T x, T y) {\\}", "T x, T y) { return x ^ y; }")
+    sub("int v, T x) {\\}", "int v, T x) { return v ^ x; }")
+}
+{ print }
diff --git a/test/graph/virtualTree.cpp b/test/graph/virtualTree.cpp
new file mode 100644
index 0000000..d256760
--- /dev/null
+++ b/test/graph/virtualTree.cpp
@@ -0,0 +1,95 @@
+#include "../util.h"
+int lca(int u, int v);
+#include <graph/virtualTree.cpp>
+
+vector<int> d, par;
+void dfs(int u, vector<vector<int>>& adj, int& counter) {
+    in[u] = counter++;
+    for (int v : adj[u]) if (v != par[u]) {
+        d[v] = d[u]+1;
+        par[v] = u;
+        dfs(v, adj, counter);
+    }
+    out[u] = counter;
+}
+
+int lca(int u, int v) {
+    if (d[u] < d[v]) swap(u, v);
+    while (d[u] > d[v]) u = par[u];
+    while (u != v) u = par[u], v = par[v];
+    return u;
+}
+
+void init(vector<vector<int>>& adj) {
+    int n = (int)sz(adj);
+    d.assign(n, 0);
+    in = par = out = d;
+    int counter = 0;
+    dfs(0, adj, counter);
+}
+
+void stress_test() {
+	for (int tries = 0; tries < 50'000; tries++) {
+		int n = Random::integer<int>(1, 50);
+		Graph<NoData> g(n);
+		g.tree();
+
+		vector<vector<int>> adj(n);
+		g.forEdges([&](int a, int b){
+			adj[a].push_back(b);
+			adj[b].push_back(a);
+		});
+
+        init(adj);
+        vector<int> ind = Random::distinct(Random::integer(1, n+1), 0, n);
+        auto [idk, tree] = virtualTree(ind);
+        vector<pair<int, int>> edges;
+        for (int i=0; i<sz(idk); i++) for (int v : tree[i]) {
+            edges.emplace_back(idk[i], idk[v]);
+        }
+
+        vector<pair<int, int>> edges2;
+        vector<bool> used(n);
+        for (int u : ind) for (int v : ind) used[lca(u, v)] = true;
+        auto dfs = [&](auto& self, int u, int p, int last) -> void {
+            if (used[u]) {
+                if (last != -1) edges2.emplace_back(last, u);
+                last = u;
+            }
+            for (int v : adj[u]) if (v != p) self(self, v, u, last);
+        };
+        dfs(dfs, 0, -1, -1);
+
+        sort(all(edges)), sort(all(edges2));
+        if (edges != edges2) cerr << "WA edge list does not match" << FAIL;
+	}
+	cerr << "tested random 50'000 tests" << endl;
+}
+
+constexpr int N = 1'000'000;
+void performance_test() {
+	timer t;
+	Graph<NoData> g(N);
+	g.tree();
+	vector<vector<int>> adj(N);
+	g.forEdges([&](int a, int b){
+		adj[a].push_back(b);
+		adj[b].push_back(a);
+	});
+
+    init(adj);
+    vector<int> ind = Random::distinct(N/2, 0, N);
+
+    ll hash = 0;
+	t.start();
+    auto [idk, tree] = virtualTree(ind);
+    hash = accumulate(all(idk), 0LL);
+	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();
+}
diff --git a/test/graph/virtualTree.cpp.awk b/test/graph/virtualTree.cpp.awk
new file mode 100644
index 0000000..fe4bc62
--- /dev/null
+++ b/test/graph/virtualTree.cpp.awk
@@ -0,0 +1,7 @@
+/\/\/ v/ { 
+    print "return {ind, tree};"
+}
+{
+    sub("void", "pair<vector<int>, vector<vector<int>>>")
+}
+{ print }