#include <bits/stdc++.h>
using namespace std;
static const int MAXN = 2e5 + 10;
static const int EPS = 1e-8;
int n;
int data[MAXN];
double arr[MAXN];
double Cal() {
  double tp = 0;
  double ret = arr[1];
  for (int i = 1; i <= n; ++i) {
    tp += arr[i];
    ret = max(tp, ret);
    if (tp < EPS + 0.0) {
      tp = 0;
    }
  }
  return ret;
}
double Solve(double x) {
  for (int i = 1; i <= n; ++i) arr[i] = data[i] - x;
  double tp1 = Cal();
  for (int i = 1; i <= n; ++i) arr[i] = -arr[i];
  double tp2 = Cal();
  double ret = max(fabs(tp1), fabs(tp2));
  return ret;
}
int main() {
  scanf("%d", &n);
  int mi = 10001, mx = -10001;
  for (int i = 1; i <= n; ++i) {
    scanf("%d", &data[i]);
    mi = min(data[i], mi);
    mx = max(data[i], mx);
  }
  double l = mi, r = mx;
  for (int i = 1; i <= 100; ++i) {
    double ll = (2 * l + r) / 3.0, rr = (2 * r + l) / 3.0;
    double tp1 = Solve(ll), tp2 = Solve(rr);
    if (tp1 > tp2) {
      l = ll;
    } else
      r = rr;
  }
  printf("%.7f", Solve(l));
}
