quicksort.go

package main

import (
    "fmt"
    "math/rand"
    "runtime"
)

func qsort(data []int, mychan chan(bool)) {
    if len(data) < 2 {
        mychan <- true
        return
    }
    pivot := data[0]
    i, j := 1, len(data)-1

    for i <= j {
        for i <= j && data[i] <= pivot {
            i++
        }
        for j >= i && data[j] >= pivot {
            j--
        }
        if i > j {
            data[0], data[j] = data[j], data[0]
            newchan := make(chan bool)

            go qsort(data[0:j], newchan)
            go qsort(data[i:], newchan)

            <- newchan
            <- newchan
            mychan <- true
        } else {
            data[i], data[j] = data[j], data[i]
        }
    }
}

func main() {
    c := make(chan bool)

    runtime.GOMAXPROCS(2)
    n := 500000
    nums := make([]int, n)
    for i:=0; i < n; i++ {
        nums[i] = rand.Intn(50)
    }
    go qsort(nums, c)
    <- c
    fmt.Println(nums)
}