Solution for "An Animal Contest 3 P3 - Monkey Market" in C++

// ./an-animal-contest-3-p2-monkey-market.yml
#include <bits/stdc++.h>
using namespace std;

// Defines
#define fs first
#define sn second
#define pb push_back
#define eb emplace_back
#define mpr make_pair
#define mtp make_tuple
#define all(x) (x).begin(), (x).end()
// Basic type definitions
#if __cplusplus == 201703L // CPP17 only things
template <typename T> using opt_ref = optional<reference_wrapper<T>>; // for some templates
#endif
using ll = long long; using ull = unsigned long long; using ld = long double;
using pii = pair<int, int>; using pll = pair<long long, long long>;
#ifdef __GNUG__
// PBDS order statistic tree
#include <ext/pb_ds/assoc_container.hpp> // Common file
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T, class comp = less<T>> using os_tree = tree<T, null_type, comp, rb_tree_tag, tree_order_statistics_node_update>;
template <typename K, typename V, class comp = less<K>> using treemap = tree<K, V, comp, rb_tree_tag, tree_order_statistics_node_update>;
// HashSet
#include <ext/pb_ds/assoc_container.hpp>
template <typename T, class Hash> using hashset = gp_hash_table<T, null_type, Hash>;
template <typename K, typename V, class Hash> using hashmap = gp_hash_table<K, V, Hash>;
const ll RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
struct chash { ll operator()(ll x) const { return x ^ RANDOM; } };
#endif
// More utilities
int SZ(string &v) { return v.length(); }
template <typename C> int SZ(C &v) { return v.size(); }
template <typename C> void UNIQUE(vector<C> &v) { sort(v.begin(), v.end()); v.resize(unique(v.begin(), v.end()) - v.begin()); }
template <typename T, typename U> void maxa(T &a, U b) { a = max(a, b); }
template <typename T, typename U> void mina(T &a, U b) { a = min(a, b); }
const ll INF = 0x3f3f3f3f, LLINF = 0x3f3f3f3f3f3f3f3f;

const int MN = 1e6 + 1;
int N,
    A[MN], res[MN];
string resi;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> N;
    for (auto i = 0; i < N; i++)
        cin >> A[i];
    sort(A, A+N);

    resi.resize(N, 'E');
    int l = 0, r = N-1, ptr = 0;
    while (l < r) {
        resi[ptr] = 'B';
        res[ptr++] = A[l];
        resi[ptr] = 'S';
        res[ptr++] = A[r];
        l++; r--;
    }
    if (l == r)
        res[ptr++] = A[l];

    for (auto i = 0; i < N; i++) cout << res[i] << " \n"[i == N-1];
    cout << (resi) << '\n';

    return 0;
}