Submission #1127008

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127008		gawr_gura	Seesaw (JOI22_seesaw)	C++20	0 / 100	9 ms	392 KiB

seesaw

#include <bits/stdc++.h>

using namespace std;

const int N = 200'000 + 10;
int n;
int a[N];

namespace sub1 { 
  bool checkCondition() { return n <= 20; }
  int pref[N];
  long double answer;
  void recursion(int l, int r, long double mi, long double ma) { 
    if (l == r) { 
      answer = min(answer, ma - mi);
      return;
    }

    { // left
      long double nMid = (long double) (pref[r] - pref[l]) / (r - l);
      recursion(l + 1, r, min(mi, nMid), max(ma, nMid));
    }
    { // right
      long double nMid = (long double) (pref[r - 1] - pref[l - 1]) / (r - l);
      recursion(l, r - 1, min(mi, nMid), max(ma, nMid));
    }
  }
  
  void solve() { 
    for (int i = 1; i <= n; ++i) pref[i] = pref[i - 1] + a[i];
    long double mid = (long double) pref[n] / n;
    answer = 1e9;
    recursion(1, n, mid, mid);

    cout << setprecision(10) << fixed << answer << "\n";
  }
}

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  cin >> n;
  for (int i = 1; i <= n; ++i) cin >> a[i];

  if (sub1::checkCondition()) { sub1::solve(); return 0; }

}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 33
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33