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 + 5;
const double INF = 2e5;
const int LIMIT = 200;
int a[N];
int n;
double getAns(double x) {
  double minSum = 0, maxSum = 0, curSum = 0;
  double ans = 0;
  for (int i = 1; i <= n; ++i) {
    curSum += a[i] - x;
    ans = max(ans, fabs(curSum - minSum));
    ans = max(ans, fabs(curSum - maxSum));
    minSum = min(minSum, curSum);
    maxSum = max(maxSum, curSum);
  }
  return ans;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 1; i <= n; ++i) cin >> a[i];
  double l = -INF, r = INF;
  double ans = INF * INF;
  for (int iter = 0; iter < LIMIT; ++iter) {
    double d = (r - l) / 3;
    double L = l + d, R = r - d;
    double vl = getAns(L), vr = getAns(R);
    ans = min(ans, min(vl, vr));
    if (vl > vr)
      l = L;
    else
      r = R;
  }
  cout << setprecision(9) << fixed << ans << endl;
  return 0;
}
