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 int MAX = 200020;
int a[MAX];
int main(void) {
  int n;
  scanf("%d", &n);
  for (int i = (0); i < (n); ++i) scanf("%d", a + i);
  auto calc = [&](double x) {
    double mini = 0, maks = 0;
    double ans = 0, cur = 0;
    for (int i = (0); i < (n); ++i) {
      cur += a[i] - x;
      ans = max(ans, abs(cur - mini));
      ans = max(ans, abs(cur - maks));
      mini = min(mini, cur);
      maks = max(maks, cur);
    }
    return ans;
  };
  double lo = 0, hi = 1e5;
  for (int it = (0); it < (100); ++it) {
    double m = (lo + hi) / 2;
    if (calc(m) > calc(m + 1e-9))
      lo = m;
    else
      hi = m;
  }
  printf("%.10lf\n", calc(lo));
  return 0;
}
