結果

問題 No.1300 Sum of Inversions
ユーザー theory_and_metheory_and_me
提出日時 2020-11-28 12:26:00
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 511 ms / 2,000 ms
コード長 8,961 bytes
コンパイル時間 2,698 ms
コンパイル使用メモリ 222,556 KB
実行使用メモリ 42,668 KB
最終ジャッジ日時 2024-09-12 22:21:18
合計ジャッジ時間 15,507 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge5
このコードへのチャレンジ
（要ログイン）

テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,812 KB
testcase_01 AC 2 ms
6,944 KB
testcase_02 AC 2 ms
6,944 KB
testcase_03 AC 386 ms
36,688 KB
testcase_04 AC 378 ms
36,420 KB
testcase_05 AC 296 ms
25,684 KB
testcase_06 AC 442 ms
39,592 KB
testcase_07 AC 423 ms
38,496 KB
testcase_08 AC 457 ms
39,876 KB
testcase_09 AC 465 ms
39,728 KB
testcase_10 AC 222 ms
23,360 KB
testcase_11 AC 229 ms
23,644 KB
testcase_12 AC 362 ms
36,028 KB
testcase_13 AC 372 ms
36,088 KB
testcase_14 AC 511 ms
42,100 KB
testcase_15 AC 468 ms
39,440 KB
testcase_16 AC 381 ms
37,332 KB
testcase_17 AC 222 ms
23,028 KB
testcase_18 AC 250 ms
24,148 KB
testcase_19 AC 309 ms
34,292 KB
testcase_20 AC 324 ms
34,652 KB
testcase_21 AC 325 ms
34,772 KB
testcase_22 AC 290 ms
25,648 KB
testcase_23 AC 429 ms
39,704 KB
testcase_24 AC 293 ms
26,336 KB
testcase_25 AC 235 ms
23,736 KB
testcase_26 AC 238 ms
23,360 KB
testcase_27 AC 269 ms
25,164 KB
testcase_28 AC 460 ms
40,472 KB
testcase_29 AC 317 ms
34,420 KB
testcase_30 AC 470 ms
39,632 KB
testcase_31 AC 291 ms
25,944 KB
testcase_32 AC 306 ms
26,396 KB
testcase_33 AC 85 ms
27,288 KB
testcase_34 AC 97 ms
27,412 KB
testcase_35 AC 232 ms
42,668 KB
testcase_36 AC 236 ms
42,668 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <bits/stdc++.h>

#include <algorithm>

#ifdef _MSC_VER
#include <intrin.h>
#endif

namespace atcoder {

namespace internal {

// @param n `0 <= n`
// @return minimum non-negative `x` s.t. `n <= 2**x`
int ceil_pow2(int n) {
    int x = 0;
    while ((1U << x) < (unsigned int)(n)) x++;
    return x;
}

// @param n `1 <= n`
// @return minimum non-negative `x` s.t. `(n & (1 << x)) != 0`
int bsf(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}

}  // namespace internal

}  // namespace atcoder

#include <cassert>
#include <vector>

namespace atcoder {

template <class S, S (*op)(S, S), S (*e)()> struct segtree {
  public:
    segtree() : segtree(0) {}
    segtree(int n) : segtree(std::vector<S>(n, e())) {}
    segtree(const std::vector<S>& v) : _n(int(v.size())) {
        log = internal::ceil_pow2(_n);
        size = 1 << log;
        d = std::vector<S>(2 * size, e());
        for (int i = 0; i < _n; i++) d[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }

    void set(int p, S x) {
        assert(0 <= p && p < _n);
        p += size;
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) {
        assert(0 <= p && p < _n);
        return d[p + size];
    }

    S prod(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        S sml = e(), smr = e();
        l += size;
        r += size;

        while (l < r) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }
        return op(sml, smr);
    }

    S all_prod() { return d[1]; }

    template <bool (*f)(S)> int max_right(int l) {
        return max_right(l, [](S x) { return f(x); });
    }
    template <class F> int max_right(int l, F f) {
        assert(0 <= l && l <= _n);
        assert(f(e()));
        if (l == _n) return _n;
        l += size;
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!f(op(sm, d[l]))) {
                while (l < size) {
                    l = (2 * l);
                    if (f(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }

    template <bool (*f)(S)> int min_left(int r) {
        return min_left(r, [](S x) { return f(x); });
    }
    template <class F> int min_left(int r, F f) {
        assert(0 <= r && r <= _n);
        assert(f(e()));
        if (r == 0) return 0;
        r += size;
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!f(op(d[r], sm))) {
                while (r < size) {
                    r = (2 * r + 1);
                    if (f(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

  private:
    int _n, size, log;
    std::vector<S> d;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};

}  // namespace atcoder

using namespace std;
using namespace atcoder;

#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x)  cerr << "Line " << __LINE__ << ": " <<  #x << " = " << (x) << "\n";
#define spa << " " <<
#define fi first
#define se second
#define ALL(a)  (a).begin(),(a).end()
#define ALLR(a)  (a).rbegin(),(a).rend()

using ld = long double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;

template<typename T> using V = vector<T>;
template<typename T> using P = pair<T, T>;
template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){os << "(" << v.first << ", " << v.second << ")"; return os;}
template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> ostream& operator<<(ostream& os, const vector<vector<T>> &v){ for(auto &e : v){os << e << "\n";} return os;}
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;

template <class T> void UNIQUE(vector<T> &x) {sort(ALL(x));x.erase(unique(ALL(x)), x.end());}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
void fail() { cout << -1 << '\n'; exit(0); }
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<"\n";}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<"\n";};

const ll INF = (1ll<<62);
// const ld EPS   = 1e-10;
// const ld PI    = acos(-1.0);
// const ll mod = (int)1e9 + 7;
const ll mod = 998244353;

template <std::uint_fast64_t Modulus> class modint {
  // long long から modint を作るときは必ず正の数にしてからコンストラクタに入れること！ 
  // そうしないとバグります
  using u64 = std::uint_fast64_t;

public:
  u64 a;

  constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {}
  constexpr u64 &value() noexcept { return a; }
  constexpr const u64 &value() const noexcept { return a; }
  constexpr modint operator+(const modint rhs) const noexcept {
    return modint(*this) += rhs;
  }
  constexpr modint operator-(const modint rhs) const noexcept {
    return modint(*this) -= rhs;
  }
  constexpr modint operator*(const modint rhs) const noexcept {
    return modint(*this) *= rhs;
  }
  constexpr modint operator/(const modint rhs) const noexcept {
    return modint(*this) /= rhs;
  }
  constexpr modint &operator+=(const modint rhs) noexcept {
    a += rhs.a;
    if (a >= Modulus) {
      a -= Modulus;
    }
    return *this;
  }
  constexpr modint &operator-=(const modint rhs) noexcept {
    if (a < rhs.a) {
      a += Modulus;
    }
    a -= rhs.a;
    return *this;
  }
  constexpr modint &operator*=(const modint rhs) noexcept {
    a = a * rhs.a % Modulus;
    return *this;
  }
  constexpr modint &operator/=(modint rhs) noexcept {
    u64 exp = Modulus - 2;
    while (exp) {
      if (exp % 2) {
        *this *= rhs;
      }
      rhs *= rhs;
      exp /= 2;
    }
    return *this;
  }
};
using mint = modint<mod>;
using vm = vector<mint>;
using vvm = vector<vm>;

ostream& operator << (ostream& os, const mint v){
os << v.value(); return os;
}

template <class T, class U> constexpr T power(T x, U exp) {
  T ret = static_cast<T>(1);
  while (exp) {
    if (exp % static_cast<U>(2) == static_cast<U>(1))
      ret *= x;
    exp /= static_cast<U>(2);
    x *= x;
  }
  return ::std::move(ret);
}

template<typename T>
tuple<map<T, int>, vector<T>> compress(const vector<T> &X){
    vector<T> decoder = X;
    sort(decoder.begin(), decoder.end());
    decoder.erase(unique(decoder.begin(), decoder.end()), decoder.end());
    map<T, int> encoder;
    for(int i=0;i<(int)decoder.size();i++) encoder[decoder[i]] = i;
    return {encoder, decoder};
}

ll op(ll x, ll y){
    return x+y;
}

ll e(){
    return 0;
}

int main(){

    ll N;
    cin >> N;
    V<ll> A(N);
    REP(i, N) cin >> A[i];

    auto [enc, dec] = compress(A);

    segtree<ll, op, e> seg_L_cnt(N), seg_L_sum(N), seg_R_cnt(N), seg_R_sum(N);
    V<ll> L_cnt(N), L_sum(N), R_cnt(N), R_sum(N);

    REP(i, N){
        ll v = enc[A[i]];
        L_cnt[i] = seg_L_cnt.prod(v+1, N);
        L_sum[i] = seg_L_sum.prod(v+1, N);

        ll val = seg_L_cnt.get(v);
        seg_L_cnt.set(v, val+1);

        val = seg_L_sum.get(v);
        seg_L_sum.set(v, val+A[i]);
    }

    for(ll i=N-1;i>=0;i--){
        ll v = enc[A[i]];
        R_cnt[i] = seg_R_cnt.prod(0, v);
        R_sum[i] = seg_R_sum.prod(0, v);

        ll val = seg_R_cnt.get(v);
        seg_R_cnt.set(v, val+1);

        val = seg_R_sum.get(v);
        seg_R_sum.set(v, val+A[i]);
    }

    // dump(L_cnt)
    // dump(L_sum)
    // dump(R_cnt)
    // dump(R_sum)

    mint res = 0;
    REP(i, N){
        res += mint(A[i]) * L_cnt[i] * R_cnt[i];
        res += mint(L_cnt[i]) * R_sum[i];
        res += mint(R_cnt[i]) * L_sum[i];
    }

    cout << res << endl;

    return 0;
}
0