func HeapSort(arr *array.List) {
fmt.Print("before heapsort: ")
arr.Print()
heap := heap.New(arr)
for i := heap.Size(); i > 0; i-- {
heap.Swap(0, i)
heap.Heapify(0, i)
}
fmt.Print("after heapsort: ")
arr.Print()
}
func QuickSort(arr *array.List, left int, right int, fn SelectPivot) {
if (right - left) <= 0 {
return
}
pvt := fn(left, right)
if pvt != right {
arr.Swap(pvt, right)
}
divider := Partition(arr, left, right)
QuickSort(arr, left, divider-1, fn)
QuickSort(arr, divider+1, right, fn)
}
func Partition(arr *array.List, left, right int) int {
i := left - 1
j := i + 1
for j < right {
if ret, _ := arr.Compare(j, right); ret < 0 {
i += 1
arr.Swap(i, j)
j += 1
} else {
j += 1
}
}
arr.Swap(right, i+1)
return i + 1
}
func Merge(arr *array.List, left int, mid int, right int) {
i := left
j := mid + 1
t := 0
temp := make([]interface{}, right-left+1)
for i <= mid && j <= right {
res, err := arr.Compare(i, j)
if err != nil {
panic(fmt.Sprintf("error in compare: %v, index i: %d, index j: %d", err.Error(), i, j))
}
if res < 0 {
temp[t], _ = arr.Get(i)
i += 1
} else {
temp[t], _ = arr.Get(j)
j += 1
}
t += 1
}
for i <= mid {
temp[t], _ = arr.Get(i)
i += 1
t += 1
}
for j <= right {
temp[t], _ = arr.Get(j)
j += 1
t += 1
}
arr.CopyRange(left, temp)
}