#include <bits/stdc++.h>
using namespace std;
const double eps = 3e-12;
int n;
double a[200005], b[200005];
double maxsum() {
  double ans = 0, tmp = 0;
  for (int i = 1; i <= n; i++) {
    tmp += b[i];
    if (tmp < 0) tmp = 0;
    ans = max(tmp, ans);
  }
  return ans;
}
double cal(double x) {
  for (int i = 1; i <= n; i++) b[i] = a[i] - x;
  double ans1 = maxsum();
  for (int i = 1; i <= n; i++) b[i] = -b[i];
  double ans2 = maxsum();
  return max(ans1, ans2);
}
int main() {
  while (scanf("%d", &n) != EOF) {
    for (int i = 1; i <= n; i++) scanf("%lf", &a[i]);
    double l = -10005, r = 10005;
    while (r - l > eps) {
      double m1 = l + (r - l) / 3.0;
      double m2 = r - (r - l) / 3.0;
      if (cal(m1) < cal(m2))
        r = m2;
      else
        l = m1;
    }
    printf("%.15f\n", cal(l));
  }
  return 0;
}
