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;
int a[200009];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
  }
  double l, r, mid;
  double maxpos, maxneg, tmpp, tmpn, ta;
  int i;
  l = -100001;
  r = 100001;
  int deepness = 0;
  while (fabs(r - l) > 0.0000000000001) {
    deepness++;
    mid = (l + r) / 2.0;
    maxpos = 0.000000000000;
    maxneg = 0.000000000000;
    tmpp = 0.000000000000;
    tmpn = 0.000000000000;
    for (i = 1; i <= n; i++) {
      ta = a[i] - mid;
      tmpp += ta;
      tmpn += -ta;
      maxpos = max(tmpp, maxpos);
      maxneg = max(tmpn, maxneg);
      tmpp = max(tmpp, 0.0000000000);
      tmpn = max(tmpn, 0.0000000000);
    }
    if (maxpos > maxneg) {
      l = mid;
    } else {
      r = mid;
    }
    if (deepness >= 100) break;
  }
  printf("%.10lf", max(maxpos, maxneg));
}
