1=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8
=1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/8
得到了8个1/2 1/6,1/12,1/20,1/30,1/42,1/56,1/8
当然了,答案不唯一,你还可以自己写一些!