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#include "../util.h"
struct UF {
UF(int n) {init(n);}
#include <datastructures/unionFind.cpp>
};
struct Naive {
vector<vector<int>> adj;
vector<int> seen;
int counter;
Naive(int n) : adj(n), seen(n), counter(0) {}
template<typename F>
void dfs(int x, F&& f) {
counter++;
vector<int> todo = {x};
seen[x] = counter;
while (!todo.empty()) {
x = todo.back();
todo.pop_back();
f(x);
for (ll y : adj[x]) {
if (seen[y] != counter) {
seen[y] = counter;
todo.push_back(y);
}
}
}
}
int findSet(int a) {
int res = a;
dfs(a, [&](int x){res = min(res, x);});
return res;
}
void unionSets(int a, int b) {
adj[a].push_back(b);
adj[b].push_back(a);
}
int size(int a) {
int res = 0;
dfs(a, [&](int /**/){res++;});
return res;
}
};
void stress_test() {
ll queries = 0;
for (int tries = 0; tries < 200; tries++) {
int n = Random::integer<int>(1, 100);
UF uf(n);
Naive naive(n);
for (int i = 0; i < n; i++) {
for (int j = 0; j < 10; j++) {
int a = Random::integer<int>(0, n);
int b = Random::integer<int>(0, n);
uf.unionSets(a, b);
naive.unionSets(a, b);
}
UF tmp = uf;
for (int j = 0; j < n; j++) {
{
auto got = tmp.size(j);
auto expected = naive.size(j);
if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
}
{
int a = Random::integer<int>(0, n);
int b = Random::integer<int>(0, n);
bool got = tmp.findSet(a) == tmp.findSet(b);
bool expected = naive.findSet(a) == naive.findSet(b);
if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
}
}
queries += n;
}
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 2'000'000;
void performance_test() {
timer t;
t.start();
UF uf(N);
t.stop();
hash_t hash = 0;
for (int operations = 0; operations < N; operations++) {
int i = Random::integer<int>(0, N);
int j = Random::integer<int>(0, N);
int k = Random::integer<int>(0, N);
int l = Random::integer<int>(0, N);
t.start();
uf.unionSets(i, j);
hash += uf.size(k);
hash += uf.size(l);
t.stop();
}
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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