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#include "../util.h"
#include <graph/scc.cpp>
void stress_test() {
ll queries = 0;
for (int tries = 0; tries < 100'000; tries++) {
int n = Random::integer<int>(1, 30);
int m = Random::integer<int>(0, max<int>(1, min<int>(100, n*(n-1) / 2 + 1)));
Graph<NoData, true> g(n);
g.erdosRenyi(m);
adj.assign(n, {});
g.forEdges([](int a, int b){
adj[a].push_back(b);
});
scc();
auto reach = [&](int a) -> vector<bool> {
vector<bool> seen(n);
auto dfs = [&](auto &&self, int u) -> void {
if (seen[u]) return;
seen[u] = true;
g.forOut(u, [&](int, int v) {
self(self, v);
});
};
dfs(dfs, a);
return seen;
};
for (int a = 0; a < n; a++) {
vector<bool> reacha = reach(a);
for (int b = 0; b < n; b++) {
if (idx[a] == idx[b]) {
if (!reacha[b]) cerr << a << " and " << b << " should be in different SCCs" << FAIL;
} else if (idx[a] < idx[b]) {
if (reacha[b]) cerr << a << " should come before " << b << " in topological order" << FAIL;
}
}
}
queries += n;
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 500'000;
constexpr int M = 2'000'000;
void performance_test() {
timer t;
Graph<NoData, true> g(N);
g.erdosRenyi(M);
adj.assign(N, {});
g.forEdges([](int a, int b){
adj[a].push_back(b);
});
t.start();
scc();
t.stop();
hash_t hash = 0;
for (int x : idx) hash += x;
if (t.time > 500) cerr << "too slow: " << t.time << FAIL;
cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
}
int main() {
stress_test();
performance_test();
}
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