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

n = int(input())
a = list(map(int, input().split()))

def f(x):
    b = [ai - x for ai in a]
    low = 0
    up = 0
    s = 0
    res = 0
    for bi in b:
        s += bi
        low = min(low, s)
        up = max(up, s)
        res = max((res, s - low, up - s))
    return res

l = -10000
r = 10000
while r - l >= 1e-6:
    llr = (l * 2 + r) / 3
    lrr = (l + r * 2) / 3
    if f(llr) > f(lrr):
        l = llr
    else:
        r = lrr

print(f(r))
