#include "../util.h" #include #include void stress_test() { ll queries = 0; timer t; for (int i = 0; i < 500; i++) { ll p = Random::prime(10000); for (ll j = 0; 2*j*j < p; j++) { for (ll b = 1; 2*b*b < p; b++) { if (gcd(j, b) != 1) continue; for (ll a : {-j, j}) { ll c = a * multInv(b, p); t.start(); auto [x, y] = recover(c, p); t.stop(); if (a != x || b != y) cerr << "got: " << x << "/" << y << ", expected: " << a << "/" << b << FAIL; queries++; } } } for (ll c = 0; c < p; c++) { t.start(); auto [x, y] = recover(c, p); t.stop(); if (y < 0) continue; if (y == 0) cerr << "error: y=0" << FAIL; ll got = (((x * multInv(y, p)) % p) + p) % p; if (got != c) cerr << "got: " << got << ", expected: " << c << FAIL; queries++; } } cerr << "tested random queries: " << queries << endl; if (t.time > 500) cerr << "too slow: " << t.time << FAIL; cerr << "tested performance: " << t.time << "ms" << endl; } int main() { stress_test(); }