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#include "../util.h"
#include <string/lyndon.cpp>
bool isLyndon(string_view s) {
string t = string(s) + string(s);
for (ll i = 1; i < ssize(s); i++) {
if (s >= t.substr(i, ssize(s))) return false;
}
return !s.empty();
}
vector<string> naive(ll n, char mi, char ma) {
vector<string> res;
auto dfs = [&](auto&& self, string pref)->void{
if (ssize(pref) <= n && isLyndon(pref)) res.push_back(pref);
if (ssize(pref) >= n) return;
for (char c = mi; c <= ma; c++) {
self(self, pref + c);
}
};
dfs(dfs, "");
return res;
}
vector<string> fast(ll n, char mi, char ma) {
vector<string> res;
string tmp(1, mi);
do {
res.push_back(tmp);
} while (next(tmp, n, mi, ma));
return res;
}
void stress_test() {
ll queries = 0;
for (ll i = 0; i < 10'000; i++) {
int n = Random::integer<int>(1, 6);
auto [l, r] = Random::pair<char>('a', 'f');
auto got = fast(n, l, r);
auto expected = naive(n, l, r);
if (got != expected) cerr << "error" << FAIL;
queries += ssize(expected);
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 9;
void performance_test() {
timer t;
t.start();
auto res = fast(N, 'a', 'f');
t.stop();
hash_t hash = ssize(res);
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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