51 lines
1.1 KiB
V
51 lines
1.1 KiB
V
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import time
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import rand
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const (
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LEN = 1000 // how many random numbers to generate
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MAX = 10000 // max of the generated numbers
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)
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fn main() {
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rand.seed(time.now().unix)
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rand.next(MAX) // skip the first
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mut arr := []int
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for _ in 0..LEN {
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arr << rand.next(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(arr mut []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(arr mut []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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