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 a[200005];
int n;
double calc(double x) {
  double ans1 = 0, sum1 = 0;
  for (int i = 1; i <= n; i++) {
    if (sum1 > 0)
      sum1 += a[i] - x;
    else
      sum1 = a[i] - x;
    ans1 = max(ans1, sum1);
  }
  double ans2 = 0, sum2 = 0;
  for (int i = 1; i <= n; i++) {
    if (sum2 < 0)
      sum2 += a[i] - x;
    else
      sum2 = a[i] - x;
    ans2 = min(ans2, sum2);
  }
  return max(ans1, abs(ans2));
}
int main() {
  int maxval = 0, minval = 20000;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", a + i);
    maxval = max(maxval, a[i]);
    minval = min(minval, a[i]);
  }
  double l = minval, r = maxval, mid1, mid2;
  for (int times = 0; times < 100; times++) {
    mid1 = (2 * l + r) / 3;
    mid2 = (l + 2 * r) / 3;
    if (calc(mid1) < calc(mid2))
      r = mid2;
    else
      l = mid1;
  }
  printf("%.7lf\n", calc(mid1));
  return 0;
}
