冒泡排序

private static void sort(int[] a) {

              for(int i=0;i<a.length;i++){

                     for(int j=a.length-1;j>i;j--){

                            if(a[j]<a[j-1]){

                                   int t=a[j];

                                   a[j]=a[j-1];

                                   a[j-1]=t;

                            }

                     }

              }