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#include "../util.h"
#include <math/modPowIterativ.cpp>
#include <math/berlekampMassey.cpp>
struct RandomRecurence {
vector<ll> f, c, cache;
RandomRecurence(int n) : f(Random::integers<ll>(n, 0, mod)), c(Random::integers<ll>(n, 0, mod)), cache(f) {}
RandomRecurence(const vector<ll>& f_, const vector<ll>& c_) : c(c_), cache(f_) {
if (cache.size() < c.size()) cerr << "wrong size" << FAIL;
cache.resize(c.size());
f = cache;
}
ll operator()(ll k){
while (ssize(cache) <= k) {
ll cur = 0;
for (ll i = 0; i < ssize(c); i++) {
cur += (c[i] * cache[ssize(cache) - i - 1]) % mod;
}
cur %= mod;
cache.push_back(cur);
}
return cache[k];
}
};
void stress_test() {
int queries = 0;
for (int i = 0; i < 50'000; i++) {
int n = Random::integer<int>(1, 10);
RandomRecurence expected(n);
ll k = Random::integer<ll>(2*n, 100);
vector<ll> s(k);
for (ll j = 0; j < k; j++) s[j] = expected(j);
auto res = BerlekampMassey(s);
RandomRecurence got(s, res);
for (ll j = 0; j < 3*k; j++) {
if (got(j) != expected(j)) cerr << "got: " << got(j) << ", expected: " << expected(j) << FAIL;
}
queries += k;
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 5'000;
void performance_test() {
timer t;
RandomRecurence f(N);
f(2*N);
t.start();
auto res = BerlekampMassey(f.cache);
t.stop();
hash_t hash = 0;
for (ll x : res) 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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