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;
int a[200005], n;
double solve(double x) {
  double sum = 0, maxisum = 0, minisum = 0;
  for (int i = 0; i < n; i++) {
    sum += (a[i] - x);
    if (sum < 0) sum = 0;
    maxisum = max(maxisum, sum);
  }
  sum = 0;
  for (int i = 0; i < n; i++) {
    sum += (a[i] - x);
    if (sum > 0) sum = 0;
    minisum = min(minisum, sum);
  }
  return max(maxisum, -minisum);
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) cin >> a[i];
  double esq = -1e18, dir = 1e18;
  int iter = 500;
  while (iter--) {
    double jump = (dir - esq) / 3;
    double t1 = esq + jump;
    double t2 = dir - jump;
    double x1 = solve(t1);
    double x2 = solve(t2);
    if (x1 > x2)
      esq = t1;
    else
      dir = t2;
  }
  printf("%.6f\n", solve(esq));
  return 0;
}
