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[200000], b[200000];
double getp(double x) {
  for (int i = 0; i < n; i++) {
    b[i] = a[i] - x;
  }
  double s = 0, r = 0;
  for (int i = 0; i < n; i++) {
    s += b[i];
    r = max(r, s);
    if (s < 0) s = 0;
  }
  s = 0;
  for (int i = 0; i < n; i++) {
    s -= b[i];
    r = max(r, s);
    if (s < 0) s = 0;
  }
  return r;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%lf", a + i);
  }
  double l = -1000, r = 1000;
  for (int step = 0; step < 120; step++) {
    double t = (r - l) / 3;
    double m1 = l + t, m2 = r - t;
    if (getp(m1) > getp(m2)) {
      l = m1;
    } else {
      r = m2;
    }
  }
  printf("%.15lf", getp(l));
  return 0;
}
