#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  auto f = [&](double x) {
    double Min = 0, Max = 0, sm = 0;
    for (int i = 0; i < n; i++) {
      sm += a[i] - x;
      Min = min(Min, sm);
      Max = max(Max, sm);
    }
    return abs(Max - Min);
  };
  double low = -1e6, high = 1e6;
  for (int i = 0; i < 200; i++) {
    double m1 = (2 * low + high) / 3;
    double m2 = (low + 2 * high) / 3;
    if (f(m1) < f(m2)) {
      high = m2;
    } else {
      low = m1;
    }
  }
  cout << setprecision(6) << fixed;
  cout << f(low) << '\n';
  return 0;
}
