多线程快速排序

本文为大家介绍下快速排序算法的多线程写法。

 @Test
    public void quickSort(){
        List<Integer> sortedList=IntStream.range(0,10).mapToObj(e-> new Random().nextInt()).collect(Collectors.toList());
        AtomicInteger flag=new AtomicInteger(1);
        new Thread(()->quickSort0(sortedList,0,sortedList.size()-1,flag)).start();
        while(flag.get()!=0){
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println(sortedList);
    }

    void quickSort0(List<Integer> sortedList, int beginIndex, int endIndex, AtomicInteger flag){
        if(beginIndex>=endIndex){
            flag.decrementAndGet();
            return;
        }
        int p=sortedList.get(endIndex);
        int minIndexRange=beginIndex-1;
        for (int i = beginIndex; i <= endIndex; i++) {
            if(sortedList.get(i)<=p){
                minIndexRange++;
                swapEle(sortedList,minIndexRange,i);
            }
        }
        final int min=minIndexRange;
        flag.decrementAndGet();
        flag.addAndGet(2);
        new Thread(()->quickSort0(sortedList,beginIndex,min-1,flag)).start();
        new Thread(()->quickSort0(sortedList,min+1,endIndex,flag)).start();
    }

    void swapEle(List<Integer> sortedList,int i,int j){
        int tmp=sortedList.get(i);
        sortedList.set(i,sortedList.get(j));
        sortedList.set(j,tmp);
    }

按此逻辑也可以对归并排序进行改造，读者可先自行研究