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 N = 2e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;
const double eps = 1e-8;
int n;
double a[N], b[N];
double check(double x) {
  for (int i = 1; i <= n; ++i) b[i] = a[i] - x;
  double sum = 0, ans1 = 0, ans2 = 0;
  for (int i = 1; i <= n; ++i) {
    sum += b[i];
    if (sum > ans1) ans1 = sum;
    if (sum < 1e-10) sum = 0;
  }
  sum = 0;
  for (int i = 1; i <= n; ++i) {
    sum += b[i];
    if (sum < ans2) ans2 = sum;
    if (sum > 1e-10) sum = 0;
  }
  return max(ans1, -ans2);
}
int main() {
  ios_base::sync_with_stdio(0);
  while (scanf("%d", &n) == 1) {
    for (int i = 1; i <= n; ++i) scanf("%lf", a + i);
    double l = -1e10, r = 1e10;
    for (int i = 1; i <= 300; ++i) {
      double ll = (l + r) / 2, rr = (ll + r) / 2;
      if (check(ll) < check(rr))
        r = rr;
      else
        l = ll;
    }
    printf("%.10f\n", check(l));
  }
  return 0;
}
