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#include "../util.h"
#include <string/suffixAutomaton.cpp>
pair<int, int> naive(string_view s, string_view t) {
int pos = 0;
int len = 0;
for (int j = 0; j < sz(t); j++) {
for (int i = 0; i < sz(s); i++) {
int cur = 0;
while (i+cur < sz(s) && j+cur < sz(t) && s[i+cur] == t[j+cur]) cur++;
if (cur > len) {
pos = j;
len = cur;
}
}
}
return {pos, len};
}
void stress_test() {
ll queries = 0;
for (int i = 0; i < 1000; i++) {
int n = Random::integer<int>(1, 100);
auto s = Random::string(n, "abc");
SuffixAutomaton sa(s);
for (int j = 0; j < 1000; j++) {
int m = Random::integer<int>(1, 100);
auto t = Random::string(m, "abc");
auto got = sa.longestCommonSubstring(t);
auto expected = naive(s, t);
if (got != expected) cerr << "error" << FAIL;
queries += m;
}
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 500'000;
void performance_test() {
timer t;
auto s = Random::string(N, "a") + Random::string(N, "ab") + Random::string(N, "abcdefghijklmnopqrstuvwxyz");
t.start();
SuffixAutomaton sa(s);
t.stop();
hash_t hash = 0;
for (ll c = 0; c < sz(s);) {
int m = Random::integer<int>(1, 1000);
s = Random::string(m, "abc");
t.start();
auto [p, l] = sa.longestCommonSubstring(s);
t.stop();
hash += l + p;
c += m;
}
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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