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;
const double eps = 1e-8;
const int N = 2e5 + 10;
double a[N], dp[N];
double aa[N];
int n;
double sub(double x) {
  memcpy(aa, a, sizeof(a));
  for (int i = 1; i <= n; i++) {
    aa[i] -= x;
  }
  double ans1 = 0, ans2 = 0, sum = 0;
  for (int i = 1; i <= n; i++) {
    if (sum < 0) sum = 0;
    sum += aa[i];
    ans1 = max(ans1, sum);
  }
  for (int i = 1; i <= n; i++) {
    aa[i] = -aa[i];
  }
  sum = 0;
  for (int i = 1; i <= n; i++) {
    if (sum < 0) sum = 0;
    sum += aa[i];
    ans2 = max(ans2, sum);
  }
  return max(ans1, ans2);
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%lf", &a[i]);
  }
  double l = -1e5, r = 1e5;
  double mid1, mid2;
  while (r - l > eps) {
    mid1 = l + (r - l) / 3;
    mid2 = r - (r - l) / 3;
    if (sub(mid1) - sub(mid2) < -eps)
      r = mid2;
    else
      l = mid1;
  }
  double ans = (mid1 + mid2) / 2;
  printf("%.8f\n", sub(l));
  return 0;
}
