/* #region Head */ #include using namespace std; using ll = long long; using ull = unsigned long long; using ld = long double; using pll = pair; using vll = vector; using vvll = vector; using vld = vector; using vvd = vector; using vs = vector; using vvs = vector; #define REP(i, m, n) for (ll i = (m), i##_len = (ll)(n); i < i##_len; ++(i)) #define REPM(i, m, n) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; ++(i)) #define REPR(i, m, n) for (ll i = (m), i##_min = (ll)(n); i >= i##_min; --(i)) #define REPD(i, m, n, d) for (ll i = (m), i##_len = (ll)(n); i < i##_len; i += (d)) #define REPMD(i, m, n, d) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; i += (d)) #define REPI(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++) #define ALL(x) begin(x), end(x) #define SIZE(x) ((ll)(x).size()) constexpr ll INF = 1'010'000'000'000'000'017LL; constexpr ll MOD = 1'000'000'007LL; // 1e9 + 7 constexpr double EPS = 1e-12; constexpr double PI = 3.14159265358979323846; // vector入力 template istream &operator>>(istream &is, vector &vec) { for (T &x : vec) is >> x; return is; } // vector出力 template ostream &operator<<(ostream &os, vector &vec) { ll len = SIZE(vec); os << "{"; for (int i = 0; i < len; i++) os << vec[i] << (i == len - 1 ? "" : ", "); os << "}"; return os; } // pair入力 template istream &operator>>(istream &is, pair &pair_var) { is >> pair_var.first >> pair_var.second; return is; } // pair出力 template ostream &operator<<(ostream &os, pair &pair_var) { os << "(" << pair_var.first << ", " << pair_var.second << ")"; return os; } // map出力 template ostream &operator<<(ostream &os, map &map_var) { os << "{"; REPI(itr, map_var) { os << *itr; itr++; if (itr != map_var.end()) os << ", "; itr--; } os << "}"; return os; } // set 出力 template ostream &operator<<(ostream &os, set &set_var) { os << "{"; REPI(itr, set_var) { os << *itr; itr++; if (itr != set_var.end()) os << ", "; itr--; } os << "}"; return os; } // dump #define DUMPOUT cerr void dump_func() { DUMPOUT << endl; } template void dump_func(Head &&head, Tail &&... tail) { DUMPOUT << head; if (sizeof...(Tail) > 0) { DUMPOUT << ", "; } dump_func(move(tail)...); } // _max の終端. template ll _max(Head &&head) { return head; } // 最大値を求める.max({}) の代わり.これにしないと vscode が壊れる. template ll _max(Head &&head, Tail &&... tail) { return max((ll)head, _max((tail)...)); } // _min の終端. template ll _min(Head &&head) { return head; } // 最小値を求める.min({}) の代わり.これにしないと vscode が壊れる. template ll _min(Head &&head, Tail &&... tail) { return min((ll)head, _min((tail)...)); } // chmax (更新「される」かもしれない値が前) template > bool chmax(T &xmax, const U &x, Comp comp = {}) { if (comp(xmax, x)) { xmax = x; return true; } return false; } // chmin (更新「される」かもしれない値が前) template > bool chmin(T &xmin, const U &x, Comp comp = {}) { if (comp(x, xmin)) { xmin = x; return true; } return false; } // container 内の最初の element のインデックスを探す template ll indexof(const Container &container, const typename Container::value_type &element) { auto iter = find(container.begin(), container.end(), element); size_t index = distance(container.begin(), iter); if (index == container.size()) { index = -1; } return index; } // ローカル用 #define DEBUG_ #ifdef DEBUG_ #define DEB #define dump(...) \ DUMPOUT << " " << string(#__VA_ARGS__) << ": " \ << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" \ << endl \ << " ", \ dump_func(__VA_ARGS__) #else #define DEB if (false) #define dump(...) #endif struct AtCoderInitialize { static constexpr int IOS_PREC = 15; static constexpr bool AUTOFLUSH = false; AtCoderInitialize() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); cout << fixed << setprecision(IOS_PREC); if (AUTOFLUSH) cout << unitbuf; } } ATCODER_INITIALIZE; /* #endregion */ template ll binarySearchIntMax(ll left, ll right, tProposition p) { if (right < left) return -1; ll mid, fn; while (left + 1 < right) { mid = (left + right) / 2; if (p(mid)) left = mid; else // fn > 0 right = mid - 1; } if (p(right)) return right; else if (p(left)) return left; else return -1; } /** N個の要素からなる正整数列 a_1, ..., a_N から k 個( k >= 1 )の要素を選び b_1, ..., b_k としたとき, あなたが得られるスコア S は k 個の要素の中央値 m (後述)を用いて次のように表されます. S = \sum_{i=1}^{k} (b_i - m) Sの最大値を求めてください. なお,答えは必ず整数となることが示せます.整数として出力してください. ※ k 個の数の中央値 m は,これを昇順に並べた数列を x_1, ..., x_k としたとき,次のように表されます. */ void solve() { ll n; cin >> n; vll a(n); cin >> a; if (n <= 2) { cout << 0 << endl; return; } sort(ALL(a)); // lsum[i] := a[0..i] の和 vll lsum(n); lsum[0] = a[0]; REP(i, 1, n) { lsum[i] = lsum[i - 1] + a[i]; } auto spansum = [&lsum](ll left, ll right) { return left == 0 ? lsum[right] : lsum[right] - lsum[left - 1]; }; ll smax = 0; REPM(i, 1, n - 2) { // 中央値 a[i] // ll s = 0; // REPM(j, 1, min(i, n - 1 - i)) // { // s += a[n - j] + a[i - j] - 2 * a[i]; // chmax(smax, s); // } ll m = a[i]; ll jmax = binarySearchIntMax(1, min(i, n - 1 - i), [&m, &spansum, &i, &n](ll j) { return spansum(n - j, n - 1) + spansum(i - j, i - 1) - 2 * j * m > 0; }); if (jmax != -1) chmax(smax, spansum(n - jmax, n - 1) + spansum(i - jmax, i - 1) - 2 * jmax * m); // 中央値 (a[i]+a[i+1])/2 // s = 0; // REPM(j, 1, min(i, (n - 1) - (i + 1))) // { // s += a[n - j] + a[i - j] - (a[i] + a[i + 1]); // chmax(smax, s); // } if (i == n - 2) continue; ll mm = a[i] + a[i + 1]; jmax = binarySearchIntMax(1, min(i, (n - 1) - (i + 1)), [&mm, &spansum, &i, &n](ll j) { return spansum(n - j, n - 1) + spansum(i - j, i - 1) - j * mm > 0; }); if (jmax != -1) chmax(smax, spansum(n - jmax, n - 1) + spansum(i - jmax, i - 1) - jmax * mm); // dump(i, mm, jmax, smax); } std::cout << smax << endl; } /** * エントリポイント. * @return 0. */ int main() { solve(); return 0; }