static void
lomuto_qsort(int arr[], int left, int right) {
if (left < right) {
int mid = lomuto_partition(arr, left, right);
lomuto_qsort(arr, left, mid-1);
lomuto_qsort(arr, mid+1, right);
}
}
/* median of 3 partition scheme
* */
static int
median_of_three_partition(int arr[], int left, int right) {
int mid = left + (right - left) / 2;
if (arr[left] >= arr[mid] && arr[left] <= arr[right]) {
swap(arr, left, right);
} else if (arr[mid] >= arr[left] && arr[mid] <= arr[right]) {
swap(arr, mid, right);
}
return lomuto_partition(arr, left, right);
}
void _quicksort(std::vector<T>& arr, const int64_t lo, const int64_t hi) {
#if 0
if (lo < hi) {
int64_t mid = lomuto_partition(arr, lo, hi);
_quicksort(arr, lo, mid-1);
_quicksort(arr, mid+1, hi);
}
#else
if (lo < hi) {
int64_t mid = hoare_partition(arr, lo, hi);
_quicksort(arr, lo, mid);
_quicksort(arr, mid+1, hi);
}
#endif
}
static void
quick_sort_with_stack(int arr[], int left, int right) {
struct stack* s = stack_new();
stack_push(s, left, right);
while (! stack_empty(s)) {
int l;
int r;
stack_pop(s, &l, &r);
if (l < r) {
int m = lomuto_partition(arr, l, r);
stack_push(s, l, m-1);
stack_push(s, m+1, r);
}
}
stack_del(s);
}
/* Random partition scheme
* */
static int
randomized_partition(int arr[], int left, int right) {
int r = rand_num(left, right);
swap(arr, r, right);
return lomuto_partition(arr, left, right);
}
