51 lines
1.0 KiB
V
51 lines
1.0 KiB
V
import time
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import rand
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const (
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gen_len = 1000 // how many random numbers to generate
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gen_max = 10000 // max of the generated numbers
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)
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fn main() {
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rand.seed(int(time.now().unix))
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rand.next(gen_max) // skip the first
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mut arr := []int{}
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for _ in 0..gen_len {
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arr << rand.next(gen_max)
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}
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println('length of random array is $arr.len')
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println('before quick sort whether array is sorted: ${is_sorted(arr)}')
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quick_sort(mut arr, 0, arr.len-1)
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println('after quick sort whether array is sorted: ${is_sorted(arr)}')
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}
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fn quick_sort(mut arr []int, l int, r int) {
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if l>=r { return }
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mut sep := l // what is sep: [...all_value<arr[sep]...sep...all_value>=arr[sep]...]
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for i in l+1..r+1 {
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if arr[i] < arr[l] {
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sep++
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swap(mut arr, i, sep)
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}
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}
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swap(mut arr, l, sep)
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quick_sort(mut arr, l, sep-1)
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quick_sort(mut arr, sep+1, r)
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}
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[inline]
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fn swap(mut arr []int, i int, j int) {
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temp := arr[i]
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arr[i] = arr[j]
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arr[j] = temp
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}
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fn is_sorted(arr []int) bool {
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for i in 0..arr.len-1 {
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if arr[i] > arr[i+1] {
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return false
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}
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}
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return true
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}
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