QuickSort

#include <cmath>
#include <iostream>
#include <vector>

using std::cin;
using std::cout;
using std::max;
using std::min;
using std::string;
using std::vector;

void swap(int* p1, int* p2) {
  int t = *p1;
  *p1 = *p2;
  *p2 = t;
}


vector<int> Partition(vector<int> aa, int xx) {
  //делим на < и >=
  int nn = aa.size();
  int ll = -1;
  for (int ii = 0; ii < nn; ++ii) {
    if (aa[ii] < xx) {
      int* p1 = &aa[ii];
      int* p2 = &aa[ll + 1];
      swap(p1, p2);
      ll++;
    }
  }
  //делим на = и >
  for (int ii = ll + 1; ii < nn; ++ii) {
    if (aa[ii] == xx) {
      int* p1 = &aa[ii];
      int* p2 = &aa[ll + 1];
      swap(p1, p2);
      ll++;
    }
  }
  return aa;
}

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  std::cout.tie(0);
  int nn;
  cin >> nn;
  vector <int> aa(nn);
  for (int& ii: aa) {
    cin >> ii;
  }
  int xx;
  cin >> xx;
  aa = Partition(aa, xx);
  for (int ii: aa) {
    cout << ii << ' ';
  }
  cout << "\n";
}
/*
17
2 2 0 2 1 2 0 2 1 0 2 1 2 2 0 0 2
1
*/