func_code_string: #include <bits/stdc++.h>   using namespace std;   namespace chu_xuan {   void swap(int &a, int &b) {     register int tmp = a;     a = b, b = tmp;   }   void read(long long &a) {     a = 0;     int b = 1, c = getchar();     while (c >  9  || c <  0 ) {       if (c ==  - ) b = -1;       c = getchar();     }     while (c >=  0  && c <=  9 ) a = (a << 3) + (a << 1) + c - 48, c = getchar();     a *= b;   }   int In() {     int a = 0, b = 1, c = getchar();     while (c >  9  || c <  0 ) {       if (c ==  - ) b = -1;       c = getchar();     }     while (c >=  0  && c <=  9 ) a = (a << 3) + (a << 1) + c - 48, c = getchar();     return a * b;   }   int max(int a, int b) { return a > b ? a : b; }   int min(int a, int b) { return a > b ? b : a; }   }  // namespace chu_xuan   using namespace chu_xuan;   const int N = 3e5;   long long n, a[N];   long long ans;   int main() {     read(n);     for (int i = 0; i < n; i++) read(a[i]);     sort(a, a + n);     for (int i = 0; i < n / 2; i++) {       ans += (a[i] + a[n - i - 1]) * (a[i] + a[n - i - 1]);     }     cout << ans;     return 0;   }   