Quick Sort Array in C++ 
  // Mon 27 Feb 15:03:30 2023 
  // FIX: a bug on pInx
int partitionX(int array[], int lo, int hi) {
  int p = array[hi];
  int pInx = lo;
  for(int i=lo; i<=hi; i++) {
	if(array[i] <= p) {
	  swap(array, i, pInx);
      if(i != hi)
          pInx++;
	}
  }
  return pInx;
}
void quickSortX(int array[], int lo, int hi) {
    if(lo < hi) {
        int pInx = partition(array, lo, hi); 
        quickSortX(array, lo, pInx - 1);
        quickSortX(array, pInx + 1, hi);
    }
}
Quick Sort Vector in C++
Importent: Pass reference of vector In Java, parameter is passed by reference in function. In C++, parameter is passed by value in function 
int partition(vector &vec, int lo, int hi){
  int ret = 0;
  int pivot = vec[hi];
  int j = -1;
  for(int i = 0; i < vec.size(); i++){
	if(vec[i] <= pivot){
	  j++;
	  swap(vec, i, j);
	}
  }
  return j;
}
				 
void quickSort(vector &vec, int lo, int hi){
  if(lo < hi){
	int pInx = partition(vec, lo, hi);
	quickSort(vec, lo, pInx - 1);
	quickSort(vec, pInx + 1, hi);
  }
}

void swap(vector &vec, int i, int j){
		  int tmp = vec[i];
		  vec[i] = vec[j];
		  vec[j] = tmp;
}

Source Code