#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-11;
vector<double> a;
double okk(double m) {
  long long n = a.size();
  double ans = 0;
  double tmp[n], pf[n];
  for (long long i = 0; i < n; i++) {
    tmp[i] = a[i] - m;
    if (i == 0)
      pf[i] = tmp[i];
    else
      pf[i] = pf[i - 1] + tmp[i];
  }
  double mn = 0;
  for (long long i = 0; i < n; i++) {
    ans = max(ans, pf[i] - mn);
    mn = min(mn, pf[i]);
    pf[i] *= -1;
  }
  mn = 0;
  for (long long i = 0; i < n; i++) {
    ans = max(ans, pf[i] - mn);
    mn = min(mn, pf[i]);
  }
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << setprecision(15) << fixed;
  long long n;
  cin >> n;
  a.resize(n);
  set<long long> st;
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
    st.insert(a[i]);
  }
  if (st.size() == 1) {
    cout << 0 << '\n';
    return 0;
  }
  double l = -1e6, r = 1e6, ans = 1e15;
  while (r - l > eps) {
    double m1 = l + (r - l) / 3;
    double m2 = r - (r - l) / 3;
    double t1 = okk(m1);
    double t2 = okk(m2);
    ans = min(ans, t1);
    ans = min(ans, t2);
    if (t1 > t2)
      l = m1;
    else
      r = m2;
  }
  cout << ans << '\n';
}
