func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename T>   ostream &operator<<(ostream &os, const vector<T> &v) {     os <<  { ;     string sep;     for (const auto &x : v) os << sep << x, sep =  ,  ;     return os <<  } ;   }   template <typename T>   ostream &operator<<(ostream &os, const set<T> &v) {     os <<  { ;     string sep;     for (const auto &x : v) os << sep << x, sep =  ,  ;     return os <<  } ;   }   template <typename T, size_t size>   ostream &operator<<(ostream &os, const array<T, size> &arr) {     os <<  { ;     string sep;     for (const auto &x : arr) os << sep << x, sep =  ,  ;     return os <<  } ;   }   template <typename A, typename B>   ostream &operator<<(ostream &os, const pair<A, B> &p) {     return os <<  (  << p.first <<  ,   << p.second <<  ) ;   }   template <typename A, typename B>   ostream &operator<<(ostream &os, const map<A, B> &v) {     os <<  { ;     string sep;     for (const auto &x : v) os << sep << x, sep =  ,  ;     return os <<  } ;   }   void dbg_out() { cerr << endl; }   template <typename Head, typename... Tail>   void dbg_out(Head H, Tail... T) {     cerr <<     << H;     dbg_out(T...);   }   mt19937 mt_rng(chrono::steady_clock::now().time_since_epoch().count());   long long rand(long long a, long long b) {     return uniform_int_distribution<long long>(a, b)(mt_rng);   }   template <long long D, typename T>   struct vec : public vector<vec<D - 1, T>> {     static_assert(D >= 1,  Dimensions invalid );     template <typename... Args>     vec(long long n = 0, Args... args)         : vector<vec<D - 1, T>>(n, vec<D - 1, T>(args...)) {}   };   template <typename T>   struct vec<1, T> : public vector<T> {     vec(long long n = 0, const T &val = T()) : vector<T>(n, val) {}   };   template <class T>   bool cmin(T &a, const T &b) {     return b < a ? a = b, 1 : 0;   }   template <class T>   bool cmax(T &a, const T &b) {     return a < b ? a = b, 1 : 0;   }   const long long N = 2e5 + 5, inf = 1e18;   struct Point {     long long x, y;     Point operator-(Point p) { return {x - p.x, y - p.y}; }     long long dist() { return x * x + y * y; }   };   bool by_x(Point &a, Point &b) { return a.x < b.x; }   bool by_y(Point &a, Point &b) { return a.y < b.y; }   long long n, ans = 1e18;   long long a[N], pref[N];   Point pt[N];   long long solve(long long L, long long R) {     if (L == R) return 1e18;     long long M = (L + R) / 2;     sort(pt + L, pt + R + 1, by_x);     long long d = min(solve(L, M), solve(M + 1, R));     long long midx = pt[L + (R - L + 1) / 2].x;     vector<Point> v;     for (long long i = L; i <= R; i++) {       if (Point{pt[i].x - midx, 0}.dist() < d) {         v.push_back(pt[i]);       }     }     sort(v.begin(), v.end(), by_y);     for (long long i = 0; i < v.size(); i++) {       for (long long j = i + 1; j < v.size(); j++) {         if (Point{0, v[i].y - v[j].y}.dist() > d) break;         d = min(d, (v[i] - v[j]).dist());       }     }     return d;   }   int32_t main() {     ios::sync_with_stdio(0);     cin.tie(0);     long long n;     cin >> n;     long long sum = 0;     for (long long i = 1, u; i <= n; i++) {       cin >> u;       sum += u;       pt[i].x = i;       pt[i].y = sum;     }     cout << solve(1, n) <<   n ;   }   