方法一:
方法二:
6 6 6 6 6 =0
6 6 6 6 6 =4
6 6 6 6 6 =11
1 2 3 4 = 2 1 2 3 4 = 3
1 2 3 4 5 6=1 1 2 3 4 5 6 7 8 9= 99