#include <bits/stdc++.h>
double a[2000005];
double f(double x, int n) {
  int i;
  double sum[200005] = {0}, maxl = 0, minl = 0;
  for (i = 1; i <= n; i++) {
    sum[i] = sum[i - 1] + a[i - 1] - x;
    if (maxl < sum[i]) maxl = sum[i];
    if (minl > sum[i]) minl = sum[i];
  }
  return maxl - minl;
}
double solve(double l, double r, int n) {
  double mid, mid2;
  int t = 200;
  while (t--) {
    mid = (l + r) / 2.0;
    mid2 = (mid + r) / 2.0;
    if (f(mid, n) < f(mid2, n))
      r = mid2;
    else
      l = mid;
  }
  return l;
}
int main() {
  int n, i;
  double hzb;
  while (~scanf("%d", &n)) {
    for (i = 0; i < n; i++) scanf("%lf", &a[i]);
    hzb = solve(-1e9, 1e9, n);
    printf("%.15lf\n", f(hzb, n));
  }
  return 0;
}
