#include <bits/stdc++.h>
using namespace std;
long long int n, m, x, k;
double a[200005];
double f(double x) {
  double max_subarray_sum_1 = 0;
  double max_subarray_sum_2 = 0;
  double cur1 = 0;
  double cur2 = 0;
  for (long long int i = 0; i < n; i++) {
    cur1 += (a[i] - x);
    cur2 -= (a[i] - x);
    if (cur1 > max_subarray_sum_1) max_subarray_sum_1 = cur1;
    if (cur2 > max_subarray_sum_2) max_subarray_sum_2 = cur2;
    if (cur1 < 0) cur1 = 0;
    if (cur2 < 0) cur2 = 0;
  }
  return max(max_subarray_sum_1, max_subarray_sum_2);
}
double ternary_search_minima(double l, double r) {
  long long int iterations = 300;
  while (iterations--) {
    double m1 = l + (r - l) / 3.0;
    double m2 = r - (r - l) / 3.0;
    if (f(m1) < f(m2))
      r = m2;
    else
      l = m1;
  }
  return f(l);
}
void purple() {
  cin >> n;
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
  }
  double l = -100000000000.0, r = 100000000000.0;
  printf("%.8lf\n", ternary_search_minima(l, r));
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long int t = 1;
  while (t--) purple();
}
