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 n, a[200000 + 1];
double x[200000 + 1];
double dp1[200000 + 1], dp2[200000 + 1], dp[200000 + 1];
double f(double delta) {
  for (int i = 0; i < n; i++) x[i] = a[i] - delta;
  dp1[0] = x[0];
  for (int i = 1; i < n; i++) {
    dp1[i] = max(dp1[i - 1] + x[i], x[i]);
  }
  dp2[0] = x[0];
  for (int i = 1; i < n; i++) {
    dp2[i] = min(dp2[i - 1] + x[i], x[i]);
  }
  dp[0] = abs(x[0]);
  for (int i = 1; i < n; i++) {
    dp[i] = abs(x[i]);
    dp[i] = max(abs(dp1[i - 1] + x[i]), dp[i]);
    dp[i] = max(abs(dp2[i - 1] + x[i]), dp[i]);
  }
  double ans = dp[0];
  for (int i = 1; i < n; i++) ans = max(ans, dp[i]);
  return ans;
}
int main() {
  while (cin >> n) {
    for (int i = 0; i < n; i++) scanf("%d", &a[i]);
    double lo = -10001, hi = 10001;
    for (int i = 0; i < 100; i++) {
      double m1 = lo + 1.0 * (hi - lo) / 3;
      double m2 = lo + 2.0 * (hi - lo) / 3;
      double x1 = f(m1), x2 = f(m2);
      if (x1 > x2)
        lo = m1;
      else
        hi = m2;
    }
    printf("%.10lf\n", f((lo + hi) / 2.0));
  }
  return 0;
}
