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#include "../util.h"
#include <math/shortModInv.cpp>
vector<vector<ll>> mat;
constexpr ll mod = 1'000'000'007;
namespace lgs {
#include <math/lgsFp.cpp>
}
vector<vector<ll>> inverseMat(const vector<vector<ll>>& m) {
int n = ssize(m);
mat = m;
for (int i = 0; i < n; i++) {
if (ssize(mat[i]) != n) cerr << "error: no square matrix" << FAIL;
mat[i].resize(2*n);
mat[i][n+i] = 1;
}
lgs::gauss(ssize(mat), ssize(mat[0]));
vector<vector<ll>> res(m);
for (int i = 0; i < n; i++) {
res[i] = vector<ll>(mat[i].begin() + n, mat[i].end());
for (int j = 0; j < n; j++) {
if (j != i && mat[i][j] != 0) cerr << "error: not full rank?" << FAIL;
if (j == i && mat[i][j] != 1) cerr << "error: not full rank?" << FAIL;
}
}
return res;
}
vector<vector<ll>> mul(const vector<vector<ll>>& a, const vector<vector<ll>>& b) {
int n = ssize(a);
int m = ssize(b[0]);
int x = ssize(b);
if (ssize(a[0]) != ssize(b)) cerr << "error: wrong dimensions" << FAIL;
vector<vector<ll>> res(n, vector<ll>(m));
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
for (int k = 0; k < x; k++) {
res[i][j] += a[i][k] * b[k][j];
res[i][j] %= mod;
}
}
}
return res;
}
//this should just not crash...
void test_square() {
ll queries = 0;
hash_t hash = 0;
for (int tries = 0; tries < 1'000; tries++) {
int n = Random::integer<int>(1, 30);
vector<vector<ll>> m(n);
for (auto& v : m) v = Random::integers<ll>(n, 0, mod);
mat = m;
lgs::gauss(ssize(mat), ssize(mat[0]));
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
hash += mat[i][j];
}
}
queries += n;
}
cerr << "tested sqaures: " << queries << " (hash: " << hash << ")" << endl;;
}
void stress_test_inv() {
ll queries = 0;
for (int tries = 0; tries < 20'000; tries++) {
int n = Random::integer<int>(1, 30);
vector<vector<ll>> m(n);
for (auto& v : m) v = Random::integers<ll>(n, 0, mod);
// m hopefully has full rank...
auto inv = inverseMat(m);
auto prod = mul(m, inv);
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (i == j && prod[i][j] != 1) cerr << "error: not inverted" << FAIL;
if (i != j && prod[i][j] != 0) cerr << "error: not inverted" << FAIL;
}
}
queries += n;
}
cerr << "tested random queries: " << queries << endl;
}
constexpr int N = 250;
void performance_test() {
timer t;
vector<vector<ll>> m(N);
for (auto& v : m) v = Random::integers<ll>(N, 0, mod);
mat = m;
t.start();
lgs::gauss(ssize(mat), ssize(mat[0]));
t.stop();
hash_t hash = 0;
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
hash += mat[i][j];
}
}
if (t.time > 500) cerr << "too slow: " << t.time << FAIL;
cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
}
int main() {
test_square();
stress_test_inv();
performance_test();
}
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