Language: C++

/* ---------- STL Libraries ---------- */

// IO library
#include <cstdio>
#include <fstream>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm library
#include <algorithm>
#include <cmath>
#include <numeric>
#include <random>

// container library
#include <array>
#include <bitset>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <tuple>
#include <vector>

/* ---------- Namespace ---------- */

using namespace std;

/* ---------- Type Abbreviation ---------- */

template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using GPQ = priority_queue<T, vector<T>, greater<T>>;

using ll = long long;

#define fst first
#define snd second
#define mp make_pair
#define mt make_tuple

#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)


/* ---------- conversion ---------- */

#define INT(c) static_cast<int>(c)
#define CHAR(n) static_cast<char>(n)
#define LL(n) static_cast<ll>(n)
#define DOUBLE(n) static_cast<double>(n)

/* ---------- container ---------- */

#define ALL(v) (v).begin(), (v).end()
#define SIZE(v) (LL((v).size()))
#define each(itr,v) for(auto (itr):(v))

#define FIND(v, k) (v).find(k) != (v).end()
#define VFIND(v, k) find(ALL(v), k) != (v).end()

#define gsort(b, e) sort(b, e, greater<decltype(*b)>())

/* ----------- debug ---------- */

template <class T>
ostream& operator<<(ostream& os, vector<T> v) {
	os << "[";
	for (auto vv : v)
		os << vv << ",";
	return os << "]";
}

template <class T>
ostream& operator<<(ostream& os, set<T> v) {
	os << "[";
	for (auto vv : v)
		os << vv << ",";
	return os << "]";
}

template <class L, class R>
ostream& operator<<(ostream& os, pair<L, R> p) {
	return os << "(" << p.fst << "," << p.snd << ")";
}

/* ---------- Constants ---------- */

// const ll MOD = 1e9 + 7;
// const int INF = 1 << 25;
// const ll INF = 1LL << 50;
// const double PI = acos(-1);
// const double EPS = 1e-10;
// mt19937 mert(LL(time(0)));

/* ---------- Short Functions ---------- */

template <typename T>
T sq(T a) {
	return a * a;
}

template <typename T>
T gcd(T a, T b) {
	if (a > b) return gcd(b, a);
	return a == 0 ? b : gcd(b % a, a);
}

template <typename T, typename U>
T mypow(T b, U n) {
	if (n == 0) return 1;
	if (n == 1) return b /* % MOD */;
	if (n % 2 == 0) {
		return mypow(b * b /* % MOD */, n / 2);
	}
	else {
		return mypow(b, n - 1) * b /* % MOD */;
	}
}

ll pcnt(ll b) {
	return __builtin_popcountll(b);
}



// const ll dx[4] = {0, -1, 1, 0};
// const ll dy[4] = {-1, 0, 0, 1};
// const ll dx[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
// const ll dy[8] = {-1, -1, -1, 0, 0, 1, 1, 1};

/* v-v-v-v-v-v-v-v-v Main Part v-v-v-v-v-v-v-v-v */

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
}




ll N;
cin >> N;
ll X[N];
REP(i, N) {
	cin >> X[i];
}
REP(i, N) {
	if (i <= N / 2 - 1) cout << X[N / 2] << endl;
	else cout << X[N / 2 - 1] << endl;
	return 0;
}

Compiler output:
a.cc:146:1: error: 'cin' does not name a type
  146 | cin >> N;
      | ^~~
a.cc:147:6: error: size of array 'X' is not an integral constant-expression
  147 | ll X[N];
      |      ^
a.cc:45:22: error: expected unqualified-id before 'for'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                      ^~~
a.cc:46:19: note: in expansion of macro 'FOR'
   46 | #define REP(i, n) FOR(i, 0, n)
      |                   ^~~
a.cc:148:1: note: in expansion of macro 'REP'
  148 | REP(i, N) {
      | ^~~
a.cc:148:5: error: 'i' does not name a type
  148 | REP(i, N) {
      |     ^
a.cc:45:39: note: in definition of macro 'FOR'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                                       ^
a.cc:148:1: note: in expansion of macro 'REP'
  148 | REP(i, N) {
      | ^~~
a.cc:148:5: error: 'i' does not name a type
  148 | REP(i, N) {
      |     ^
a.cc:45:48: note: in definition of macro 'FOR'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                                                ^
a.cc:148:1: note: in expansion of macro 'REP'
  148 | REP(i, N) {
      | ^~~
a.cc:45:22: error: expected unqualified-id before 'for'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                      ^~~
a.cc:46:19: note: in expansion of macro 'FOR'
   46 | #define REP(i, n) FOR(i, 0, n)
      |                   ^~~
a.cc:151:1: note: in expansion of macro 'REP'
  151 | REP(i, N) {
      | ^~~
a.cc:151:5: error: 'i' does not name a type
  151 | REP(i, N) {
      |     ^
a.cc:45:39: note: in definition of macro 'FOR'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                                       ^
a.cc:151:1: note: in expansion of macro 'REP'
  151 | REP(i, N) {
      | ^~~
a.cc:151:5: error: 'i' does not name a type
  151 | REP(i, N) {
      |     ^
a.cc:45:48: note: in definition of macro 'FOR'
   45 | #define FOR(i, a, b) for (ll i = (a); i < (b); i++)
      |                                                ^
a.cc:151:1: note: in expansion of macro 'REP'
  151 | REP(i, N) {
      | ^~~