冒泡排序

 1     public void bubbleSort(int[] arr) {
 2         if (arr == null || arr.length == 0)
 3             return ;
 4         int temp = 0;
 5         //从小到大排序
 6         for (int i = 0; i < arr.length; i++) {
 7             //从后到前比较
 8             for (int j = arr.length - 1; j > i; j--){
 9                 if (arr[i] > arr[j]) {
10                     temp = arr[i];
11                     arr[i] = arr[j];
12                     arr[j] = temp;
13                 }
14             }
15         }
16     }