38 lines
726 B
Go
38 lines
726 B
Go
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package sorting
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type shell struct{}
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func (*shell) Sort(items Sortable) {
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len := items.Len()
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gap := 1
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// Calculating gap maximum value.
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// This is for "Sedgewick gap sequence" variation.
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// Another sequences can be used
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for gap < len/3 {
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gap = gap*3 + 1
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}
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// This loop needed to progressively degrease gap until siple insertion
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// sort will be used
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for gap >= 1 {
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// Insertion sort loop
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for i := gap; i < len; i++ {
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// Instead of comparing adjacent elements we compare
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// gap distance elements and swap them
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for j := i; j >= gap && items.Less(j, j-gap); j -= gap {
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items.Swap(j, j-gap)
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}
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}
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// "Sedgewick gap sequence"
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gap = gap / 3
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}
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}
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func NewShell() Sorter {
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return &shell{}
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}
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