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[100050], b[100050];
double getans() {
  double t = 0, res = b[1];
  for (int i = 1; i <= n; i++) {
    t += b[i];
    res = max(res, t);
    if (t < 0) t = 0;
  }
  return res;
}
double sol(double x) {
  for (int i = 1; i <= n; i++) b[i] = a[i] - x;
  double tmp = getans();
  for (int i = 1; i <= n; i++) b[i] = -b[i];
  double tmp1 = getans();
  return max(fabs(tmp), fabs(tmp1));
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%lf", &a[i]);
  double l = -1.0 * 0x3f3f3f3f, r = 1.0 * 0x3f3f3f3f;
  for (int i = 0; i < 100; i++) {
    double mid = (l + r) / 2;
    double mid1 = (r + mid) / 2;
    double ans = sol(mid), ans1 = sol(mid1);
    if (ans1 > ans)
      r = mid1;
    else
      l = mid;
  }
  printf("%.8lf\n", sol(l));
  return 0;
}
