排序之冒泡排序

public class bubbleSort {
    public static void main(String[] args) {
        Random r = new Random();
        int[] arr = new int[10000];
        for(int i = 0;i<arr.length;i++) {
            arr[i] = r.nextInt();
        }
        long t1 = System.currentTimeMillis();
        BubbleSort1(arr);
        long t2 = System.currentTimeMillis();
        System.out.println(t2);
        System.out.println(t1);
        System.out.println(t2 - t1);
        long t3 = System.currentTimeMillis();
        BubbleSort2(arr);
        long t4 = System.currentTimeMillis();
        System.out.println(t3);
        System.out.println(t4);
        System.out.println(t4 - t3);
    }
    
    public static void BubbleSort1(int arr[]) {
        for(int i = 1;i<arr.length;i++) {
            for(int j = 0;j<arr.length-i;j++) {
                if(arr[j]>arr[j+1]) {
                    int temp = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = temp;
                }
            }
        }
    }
//    优化算法：我们加一个条件判断它是否交换，如果没有交换，那么就说明他已经排好序
    public static void BubbleSort2(int arr[]) {
        for(int i = 1;i<arr.length;i++) {
            Boolean b = false;
            for(int j = 0;j<arr.length-i;j++) {
                if(arr[j]>arr[j+1]) {
                    int temp = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = temp;
                    b = true;
                }
            }
            if(b == true) break;
        }
    }
}