selectionSort<E> function

void selectionSort<E>(
  1. List<E> list, {
  2. int? begin,
  3. int? end,
  4. Comparator<E>? compare,
})

Sorts the list of numbers using the selection sort algorithm.

Parameters

  • list is any list of items to be sorted.
  • To perform partial sorting, you can specify the begin or end.
  • begin is the start index of the range to be sorted.
  • If begin is negative, range starts at the 0
  • If begin is not below the length of the list, range will be empty.
  • end is the final index if the range to be sorted. It is exclusive.
  • If end is above the length of the list, it will be ignored.
  • If end is negative, the absolute value of it will be subtracted from the length of the list to determine where the range ends.
  • If end is not greater than the begin, the range will be empty.
  • compare is a custom compare to order the list elements. If it is null and list items are not Comparable, TypeError is thrown.

Details

The selection sort algorithm sorts the list in an increasing order by finding the minimum element from the unordered range and putting it at the beginning in each iteration.

Although, it is faster than bubble sort, it requires more comparisons than other O(n^2) algorithms such as insertion sort. Therefore, it is not very useful in practice.

Complexity: Time O(n^2) | Space O(1)

Implementation

void selectionSort<E>(
  List<E> list, {
  int? begin,
  int? end,
  Comparator<E>? compare,
}) {
  int b, e;
  int n = list.length;

  // Find the range given the parameters.
  b = 0;
  e = n;
  if (begin != null && b < begin) {
    b = begin;
  }
  if (end != null && end < e) {
    e = end;
    if (e < 0) e += n;
  }

  if (compare == null) {
    selectorSortDefault(list, b, e);
  } else {
    selectorSortCustom(list, b, e, compare);
  }
}