boilerplate.cpp

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;

#define repeat(_i, _x) for (int _i = 0; _i < (_x); ++_i)
#define for_range(_i, _start, _end, _itr)                                      \
    for (int _i = (_start); _i < (_end); _i += _itr)

void setIO(const string str = "") {
    ios::sync_with_stdio(false);
#ifdef LOCAL // compile with -DLOCAL
    cout << "compiled locally" << endl;
    if (str.empty())
        freopen("test.in", "r", stdin);
    else {
        freopen((str + ".in").c_str(), "r", stdin);
    }
#else
    if (!str.empty()) {
        freopen((str + ".in").c_str(), "r", stdin);
        freopen((str + ".out").c_str(), "w", stdout);
    }
#endif
}

#define _range(_x) _x.begin(), _x.end()
#define _rrange(_x) _x.rbegin(), _x.rend()

int main() {
    setIO();

    int len;
    cin >> len;

    vector<int> v(len);

    repeat(i, len) {
        cin >> v[i];
    }
}