selection.go

package sorting

// Selection Sort
// First, find the smallest item int the slice, and swap it with the first entry
// Then, find the next smallest item and swap it with the second entry
// Continue in this way until the entire slice is sorted

// This method is called selection sort because it works by repeatedly selecting
// the smallest remaining items

func SelectionSort(x Sortable) {
	n := x.Len()
	for i := 0; i < n; i++ {
		ithMin := i // the i-th smallest item's index
		for j := i + 1; j < n; j++ {
			if x.Less(j, ithMin) {
				ithMin = j
			}
		}
		x.Swap(i, ithMin)
	}
}

type Selection struct{}

func NewSelection() Sorter {
	return Selection{}
}

// Implements Sorter

func (s Selection) SortInts(x []int) {
	SelectionSort(IntSortSlice(x))
}
func (s Selection) SortFloat64s(x []float64) {
	SelectionSort(Float64SortSlice(x))
}
func (s Selection) SortStrings(x []string) {
	SelectionSort(StringSortSlice(x))
}