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 n;
double a[200100], b[200100];
const double eps = 1e-6;
double getmax() {
  double ans = 0, sum = 0;
  for (int i = 1; i <= n; i++) {
    sum = sum + b[i];
    if (sum < 0) sum = 0;
    ans = max(ans, sum);
  }
  return ans;
}
double calc(double x) {
  for (int i = 1; i <= n; i++) b[i] = a[i] - x;
  double ans = getmax();
  for (int i = 1; i <= n; i++) b[i] = -b[i];
  ans = max(ans, getmax());
  return ans;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%lf", &a[i]);
  double l = -10000.0, r = 10000.0, mid;
  for (int i = 0; i < 100; i++) {
    double m1 = l + (r - l) / 3;
    double m2 = r - (r - l) / 3;
    if (calc(m1) < calc(m2))
      r = m2;
    else
      l = m1;
  }
  printf("%.6f\n", calc(l));
  return 0;
}
