冒泡排序

public class Demo08 {
    public static void main(String[] args) {
        int[] arr = {1, 2, 99, 4, -5, 0, 77, 123, -3};
        int[] arr1 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

        System.out.println(Arrays.toString(sort(arr1)));
    }

    public static int[] sort (int[] arr) {
        int temp = 0;
        boolean flag = false; // 优化点
        for (int i = 0; i < arr.length - 1; i++) {
            for (int j = 0; j < arr.length - 1 - i; j++) {
                if (arr[j] > arr[j+1]) {
                    temp = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = temp;
                    flag = true;
                }
            }
            if (flag == false) { // 最好的情况，所有元素都已经排好序了，只需要经过一轮
                break;
            }
        }
        return arr;
    }
}