제출 #75447

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
75447		WLZ	Vudu (COCI15_vudu)	C++17	140 / 140	307 ms	27968 KiB

vudu

#include <iostream>
#include <vector>
#include <algorithm>
#include <map>

using namespace std;

template<typename T>
class fenwick {
  private:
    int n;
    vector<T> fenw;
  public:

    fenwick(int _n) : n(_n) {
      fenw.resize(n);
    }

    void modify(int x, T v) {
      while (x < n) {
        fenw[x] += v;
        x |= (x + 1);
      }
    }

    T get(int x) {
      T v{};
      while (x >= 0) {
        v += fenw[x];
        x = (x & (x + 1)) - 1;
      }
      return v;
    }
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector< pair<long long, int> > a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i].first;
    a[i].second = i;
  }
  long long p;
  cin >> p;
  for (int i = 0; i < n; i++) {
    a[i].first -= p;
  }
  for (int i = 1; i < n; i++) {
    a[i].first += a[i - 1].first;
  }
  sort(a.begin(), a.end());
  vector<int> rep(n);
  rep[a[0].second] = 0;
  for (int i = 1; i < n; i++) {
    rep[a[i].second] = rep[a[i - 1].second];
    if (a[i].first > a[i - 1].first) {
      rep[a[i].second]++;
    }
  }
  fenwick<long long> fenw(n + 1);
  long long ans = 0ll;
  for (int i = 0; i < n; i++) {
    if (a[i].first >= 0) {
      ans++;
    }
    ans += fenw.get(rep[i]);
    fenw.modify(rep[i], +1);
  }
  cout << ans << endl;
  return 0;
}

• Subtask 1: 140 / 140