func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2e5 + 5;   const int M = 505;   const int nmax = 1e3 + 5;   const long long inf = 1e9;   const int mod = 1e9 + 7;   const long long P = 31;   const int K = 20;   const long double eps = 1e-9;   const int dx[4] = {-1, 0, 1, 0};   const int dy[4] = {0, -1, 0, 1};   set<double> s;   long long a[N];   int main() {     ios_base::sync_with_stdio(false);     long long sum;     int n;     cin >> n;     for (int i = 0; i < n; ++i) {       cin >> a[i];       s.insert(double(a[i]));       sum += a[i];     }     sort(a, a + n);     long long sm = a[(n >> 1) - 1], bg = a[n >> 1];     while ((int)s.size() > 2) {       double med = 1.0 * (sm + bg) / 2.0;       auto ib = s.begin();       auto ie = s.end();       ie--;       if ((med - *ib) < (*ie - med)) {         auto it = s.lower_bound(sm);         sm = *(--it);         it++;         sum -= *ie;         sum -= *it;         s.erase(ie);         s.erase(it);       } else {         auto it = s.lower_bound(bg);         bg = *(++it);         it--;         sum -= *ib;         sum -= *it;         s.erase(ib);         s.erase(it);       }     }     cout << bg - sm <<   n ;     return 0;   }   