冒泡排序

private static void maopao() {

              int[] arr=new int[]{4,5,61,40,7,91};

              for(int i=1;i<arr.length;i++){  //控制轮数

                     for(int j=1;j<arr.length-i;j++){   //控制每轮的次数

                            if(arr[j-1]>arr[j]){

                                   int t=arr[j-1];

                                   arr[j-1]=arr[j];

                                   arr[j]=t;

                            }

                     }

              }

              System.out.println(Arrays.toString(arr));

       }