#include <bits/stdc++.h>
using namespace std;
int n;
double a[200005], b[200005];
double l = -10001, r = 10001;
const double eps = 2e-12;
double solve(double x) {
  for (int i = 1; i <= n; ++i) b[i] = a[i] - x;
  double res = 0, tmp = 0;
  for (int i = 1; i <= n; ++i) {
    if (tmp < 0) tmp = 0;
    tmp += b[i];
    res = max(res, tmp);
  }
  tmp = 0;
  for (int i = 1; i <= n; ++i) {
    if (tmp < 0) tmp = 0;
    tmp -= b[i];
    res = max(res, tmp);
  }
  return res;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) {
    scanf("%lf", &a[i]);
  }
  while (r > eps + l) {
    double ll = (2 * l + r) / 3, rr = (l + 2 * r) / 3;
    double lll = solve(ll);
    double rrr = solve(rr);
    if (lll < rrr)
      r = rr;
    else
      l = ll;
  }
  cout << fixed << setprecision(12) << solve((l + r) / 2) << endl;
}
