void swap(double &x, double &y){
//ARG:
//DESC: The values stored in x and y are exchanged.
  double tmp = x;
  x = y;
  y = tmp;
}

void bubbleSort(double a[], int n){
//ARG: n = length(a)
//DESC: a[0..n-1] is increasingly sorted.
  int i = n-1;
  bool sorted = false;
  while(!sorted && i > 0){
    sorted = true;
    for(int j=0; j < i; j++){
      if(a[j] > a[j+1]){
        swap(a[j], a[j+1]);
        sorted = false;
      }
    }
    i = i-1;
  }
}