void fill_random(vector& mx, T a, T b) {
if (a > b) swap(a, b);
uniform_int_distribution uid(a, b);
mt19937 gen{ random_device()() };
for (auto& row : mx) {
for (auto& x : row) {
x = uid(gen);
}
}
}
void show(const vector& mx, const streamsize w) {
for (const auto& row : mx) {
for (auto x : row) {
cout