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#include "../util.h"
constexpr ll EPS = 0;
#define double ll
#define polar polar<ll>
#include <geometry/formulas.cpp>
#undef polar
#undef double
// Liegt p auf der Strecke a-b?
bool pointOnLineSegment(pt a, pt b, pt p) {
if (cross(a, b, p) != 0) return false;
double dist = norm(a - b);
return norm(a - p) <= dist && norm(b - p) <= dist;
}
// Test auf Streckenschnitt zwischen a-b und c-d.
bool segmentIntersection(pt a, pt b, pt c, pt d) {
if (ccw(a, b, c) == 0 && ccw(a, b, d) == 0)
return pointOnLineSegment(a,b,c) ||
pointOnLineSegment(a,b,d) ||
pointOnLineSegment(c,d,a) ||
pointOnLineSegment(c,d,b);
return ccw(a, b, c) * ccw(a, b, d) <= 0 &&
ccw(c, d, a) * ccw(c, d, b) <= 0;
}
#include <geometry/segmentIntersection.cpp>
vector<seg> randomSegs(int n, ll range) {
auto ps = Random::points<ll>(n, -range, range);
vector<seg> segs(n);
for (int i = 0; i < n; i++) {
pt b;
do {
b = Random::point<ll>(-pow(range, 0.8), pow(range, 0.8));
} while(norm(b) == 0);
segs[i] = {ps[i], ps[i] + b, i};
}
return segs;
}
bool naive(vector<seg>& segs) {
for (ll i = 0; i < ssize(segs); i++) {
for (ll j = 0; j < i; j++) {
if (segmentIntersection(segs[i].a, segs[i].b, segs[j].a, segs[j].b)) return true;
}
}
return false;
}
void stress_test(ll range) {
ll queries = 0;
ll intersection = 0;
ll notIntersection = 0;
for (int tries = 0; tries < 100'000; tries++) {
int n = Random::integer<int>(2, 100);
auto segs = randomSegs(n, range);
auto [a, b] = intersect(segs);
bool got = a >= 0;
if (got != (b >= 0)) cerr << "error: invalid ans" << FAIL;
auto expected = naive(segs);
if (got != expected) cerr << "error: intersection not found" << FAIL;
if (got && !segmentIntersection(segs[a].a, segs[a].b, segs[b].a, segs[b].b)) cerr << "error: no intersection" << FAIL;
queries += n;
intersection += got;
notIntersection += !got;
}
cerr << "tested random queries: " << queries << "(" << intersection << ":" << notIntersection << ")" << endl;
}
constexpr int N = 1'000'000;
void performance_test() {
timer t;
auto segs = randomSegs(N, 1'000'000'000);
t.start();
hash_t hash = intersect(segs).first;
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(100);
stress_test(1'000'000'000);
performance_test();
}
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