10
-405 -230 252 -393 -390 -259 97 163 81 -129
 3
10000 -10000 10000
 1
-10000
 20
-16 -23 29 44 -40 -50 -41 34 -38 30 -12 28 -44 -49 15 50 -28 38 -2 0

702.333333333333712
 10000.000000000016371
 0.000000000000000
 113.875000000000043

#include <bits/stdc++.h>
using namespace std;
int arr[300005];
double temp[300005];
int n;
double value(double x) {
  for (int i = 0; i < n; i++) {
    temp[i] = arr[i] * 1.0 - x;
  }
  double maxv = temp[0];
  double currmax = temp[0];
  for (int i = 1; i < n; i++) {
    if (currmax > 0) {
      currmax += temp[i];
    } else {
      currmax = temp[i];
    }
    maxv = max(maxv, currmax);
  }
  double minv = temp[0];
  currmax = temp[0];
  for (int i = 1; i < n; i++) {
    if (currmax < 0) {
      currmax += temp[i];
    } else {
      currmax = temp[i];
    }
    minv = min(minv, currmax);
  }
  return max(abs(maxv), abs(minv));
}
double binary_search(double low, double high) {
  while ((high - low) > 1e-7) {
    double mid = (low + high) / 2.0;
    double a = value(mid);
    double b = value(mid + 1e-7);
    double c = value(mid - 1e-7);
    if (a < b && a < c)
      return a;
    else if (a > b) {
      low = mid;
    } else
      high = mid;
  }
}
int main() {
  scanf("%d", &n);
  ;
  for (int i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
    ;
  }
  double x = binary_search(-100000000, 1000000000);
  printf("%.7f\n", x);
}
