UVa 299 Train Swapping

UVa 299 Train Swapping

冒泡排序，并记录交换次数。
以下是我的代码：

#include < algorithm >
#include < cstdio >
using   namespace  std;
const   int  kMaxn( 57 );

int  main()
{
     /*
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
    // */

     int  T;
    scanf( " %d " , & T);
     while (T -- )
    {
         int  n;
        scanf( " %d " , & n);
         int  r[kMaxn];
         for ( int  i = 1 ;i <= n;i ++ )
            scanf( " %d " , & r[i]);

         int  ans( 0 );
         for ( int  i = n;i >= 2 ;i -- )
             for ( int  j = 1 ;j < i;j ++ )
                 if (r[j] > r[j + 1 ])
                {
                    swap(r[j],r[j + 1 ]);
                    ans ++ ;
                }

        printf( " Optimal train swapping takes %d swaps.\n " ,ans);
    }

     return   0 ;
}