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#include "../util.h"
#include <datastructures/unionFind.cpp>
#include <graph/cycleCounting.cpp>
int naive(const vector<pair<int, int>>& edges, int n) {
int res = 0;
for (int i = 1; i < (1ll << ssize(edges)); i++) {
vector<int> deg(n);
init(n);
int cycles = 0;
for (int j = 0; j < ssize(edges); j++) {
if (((i >> j) & 1) != 0) {
auto [a, b] = edges[j];
deg[a]++;
deg[b]++;
if (findSet(a) != findSet(b)) {
unionSets(a, b);
} else {
cycles++;
}
}
}
bool ok = cycles == 1;
for (auto d : deg) ok &= d == 0 || d == 2;
if (ok) res++;
}
return res;
}
void stress_test() {
ll queries = 0;
for (int tries = 0; tries < 50'000; tries++) {
int n = Random::integer<int>(1, 8);
int m = Random::integer<int>(0, min<int>(15, n*(n-1) / 2 + 1));
Graph<NoData, 0, 1, 1> g(n);
g.erdosRenyi(m);
vector<pair<int, int>> edges;
cycles cyc(n);
g.forEdges([&](int a, int b){
edges.emplace_back(a, b);
cyc.addEdge(a, b);
});
int expected = naive(edges, n);
int got = cyc.count();
if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
queries += n;
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 100;
constexpr int M = 20;
void performance_test() {
timer t;
Graph<NoData> g(N);
g.tree();
g.erdosRenyi(M);
cycles cyc(N);
g.forEdges([&](int a, int b){
cyc.addEdge(a, b);
});
t.start();
hash_t hash = cyc.count();
cerr << ssize(cyc.base) << endl;
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();
}
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