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#include "../util.h"
struct edge {
ll from, to, id;
};
#define Edge edge
#include <graph/articulationPoints.cpp>
#undef Edge
vector<bool> naiveBridges(const vector<pair<int, int>>& edges) {
vector<bool> res(sz(edges));
vector<int> seen(sz(adj), -1);
for (int i = 0; i < sz(edges); i++) {
auto [a, b] = edges[i];
vector<int> todo = {a};
seen[a] = i;
while (!todo.empty() && seen[b] != i) {
int c = todo.back();
todo.pop_back();
for (auto e : adj[c]) {
if (e.id == i) continue;
if (seen[e.to] == i) continue;
seen[e.to] = i;
todo.push_back(e.to);
}
}
res[i] = seen[b] != i;
}
return res;
}
void stress_test_bridges() {
ll queries = 0;
for (int tries = 0; tries < 200'000; tries++) {
int n = Random::integer<int>(1, 30);
int m = Random::integer<int>(0, max<int>(1, min<int>(300, n*(n-1) / 2 + 1)));
Graph<NoData, 0, 1> g(n);
g.erdosRenyi(m);
adj.assign(n, {});
vector<pair<int, int>> edges;
g.forEdges([&](int a, int b){
adj[a].push_back({a, b, sz(edges)});
adj[b].push_back({b, a, sz(edges)});
edges.emplace_back(a, b);
});
auto expected = naiveBridges(edges);
find();
vector<bool> got(sz(edges));
for (auto e : bridges) {
if (got[e.id]) cerr << "error: duclicate" << FAIL;
got[e.id] = true;
}
if (got != expected) cerr << "error" << FAIL;
queries += n;
}
cerr << "tested random queries: " << queries << endl;
}
int main() {
stress_test_bridges();
}
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