debug.h

#define FOR(i, a, b) for (int i = (a), _##i = (b); i <= _##i; ++i)
#define REP(i, a) for (int i = 0, _##i = (a); i < _##i; ++i)
 
#define DEBUG(X) { auto _X = (X); std::cerr << "L" << __LINE__ << ": " << #X << " = " << (_X) << std::endl; }
#define PR(A, n) { std::cerr << "L" << __LINE__ << ": " << #A << " = "; FOR(_, 1, n) std::cerr << A[_] << ' '; std::cerr << std::endl; }
#define PR0(A, n) { std::cerr << "L" << __LINE__ << ": " << #A << " = "; REP(_, n) std::cerr << A[_] << ' '; std::cerr << std::endl; }

// For printing std::pair, container, etc.
// Copied from https://quangloc99.github.io/2021/07/30/my-CP-debugging-template.html
template<class U, class V> std::ostream& operator << (std::ostream& out, const std::pair<U, V>& p) {
    return out << '(' << p.first << ", " << p.second << ')';
}

template<class Con, class = decltype(begin(std::declval<Con>()))>
typename std::enable_if<!std::is_same<Con, std::string>::value, std::ostream&>::type
operator << (std::ostream& out, const Con& con) {
    out << '{';
    for (auto beg = con.begin(), it = beg; it != con.end(); it++) {
        out << (it == beg ? "" : ", ") << *it;
    }
    return out << '}';
}
template<size_t i, class T> std::ostream& print_tuple_utils(std::ostream& out, const T& tup) {
    if (i == std::tuple_size<T>::value) return out << ")"; 
    else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); 
}
template<class ...U> std::ostream& operator << (std::ostream& out, const std::tuple<U...>& t) {
    return print_tuple_utils<0, std::tuple<U...>>(out, t);
}