C++ Blatt 9 A22.cc

#include <iostream>
#include <random>
using namespace std;

double random_number() {
  return double (rand()) / RAND_MAX;
}

int partition(double A[], int s, int t) {
  double pivot = A[s];
  int l = s;
  for (int i = s + 1; i <= t; i++) {
    if (A[i] < pivot) {
      l = l + 1;
      swap(A[i], A[l]);
    }
  }
  swap(A[s], A[l]);
  return l;
}
  
void quicksort(double A[], int s, int t) {
  if (t <= s)
    return;

  int p = partition(A, s, t);

  quicksort(A, s, p - 1);
  quicksort(A, p + 1, t);
}

int main () {
  srand(time(NULL));

  double A[1000];

  for (auto &d: A)
    d = random_number();

  for (auto d: A)
    cout << d << " ";

  quicksort(A, 0, 999);

  cout << endl << endl << "Sorted: " << endl << endl;

  for (auto d: A)
    cout << d << " ";  
}