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 MAXN = 200005;
int n, a[MAXN];
double getWeakness(double x) {
  double cur = 0.0, maxv = 0.0, minv = 0.0, ret = 0.0;
  for (int i = 1; i <= n; ++i) {
    cur += a[i] + x;
    ret = max(ret, fabs(maxv - cur));
    ret = max(ret, fabs(cur - minv));
    maxv = max(maxv, cur);
    minv = min(minv, cur);
  }
  return ret;
}
int main() {
  int i;
  double l, r, mid1, mid2;
  scanf("%d", &n);
  for (i = 1; i <= n; ++i) scanf("%d", &a[i]);
  l = -10000.0, r = 10000.0;
  for (i = 1; i <= 100; ++i) {
    mid1 = l + (r - l) / 3.0;
    mid2 = r - (r - l) / 3.0;
    if (getWeakness(mid1) > getWeakness(mid2))
      l = mid1;
    else
      r = mid2;
  }
  printf("%.15f\n", getWeakness(r));
  return 0;
}
