#include <bits/stdc++.h>   using namespace std;   const int N = 2e5 + 5;   int n;   double a[N];   double max_poor(double x) {     int i;     double pre, mpre, ret = 0;     pre = mpre = 0;     for (i = 0; i < n; i++) {       pre += a[i] - x;       ret = max(ret, abs(pre - mpre));       mpre = min(mpre, pre);     }     pre = mpre = 0;     for (i = 0; i < n; i++) {       pre += a[i] - x;       ret = max(ret, abs(pre - mpre));       mpre = max(mpre, pre);     }     return ret;   }   int main() {     cin.tie(0);     ios::sync_with_stdio(0);     int i;     double l = 0.0, h = 0.0, m1, m2;     cin >> n;     for (i = 0; i < n; h = max(h, abs(a[i])), i++) cin >> a[i];     l = -h;     for (i = 0; i < 300; i++) {       m1 = l + (h - l) / 3;       m2 = h - (h - l) / 3;       if (max_poor(m1) > max_poor(m2))         l = m1;       else         h = m2;     }     printf( %.17f n , max_poor(l));     return 0;   }   