#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-8;
double a[200010];
double b[200010];
int n;
double Cal(double x) {
  double Max = 0, Min = 0;
  double best = 0.0;
  for (int i = 1; i <= n; ++i) {
    Max = max(0.0, Max) + (a[i] - x);
    best = max(best, fabs(Max));
    Min = min(0.0, Min) + (a[i] - x);
    best = max(best, fabs(Min));
  }
  return best;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%lf", &a[i]);
  double left = -1000000, right = 1000000;
  double mid, midmid;
  for (int i = 0; i < 300; i++) {
    mid = (left + right) / 2;
    midmid = (mid + right) / 2;
    if (Cal(mid) < Cal(midmid))
      right = midmid;
    else
      left = mid;
  }
  printf("%lf\n", Cal(right));
  return 0;
}
