#include <bits/stdc++.h>
using namespace std;
int n;
double a[200000];
double b[200000];
double kadane() {
  double ans = b[0];
  double con = b[0];
  for (int i = 1; i < n; i++) {
    con = max(con + b[i], b[i]);
    ans = max(ans, con);
  }
  return ans;
}
double f(double x) {
  for (int i = 0; i < n; i++) {
    b[i] = a[i] - x;
  }
  double ans = abs(kadane());
  for (int i = 0; i < n; i++) {
    b[i] = -b[i];
  }
  ans = max(ans, abs(kadane()));
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  double L = -10000;
  double R = 10000;
  for (int i = 0; i < 100; i++) {
    double M1 = (2 * L + R) / 3;
    double M2 = (L + 2 * R) / 3;
    f(M1) < f(M2) ? R = M2 : L = M1;
  }
  cout << fixed << setprecision(7) << min(f(L), f(R)) << endl;
  return 0;
}
