res, mid = [], [] arr = [1,1,1,2,2,3,1,1] arr.each{|i| unless mid.empty? || i == mid.last; res << mid; mid = []; end; mid << i}; res << mid 这样 OK 么？

a = [1,1,1,2,2,3,1,1]
a.chunk{|x|x}.map &:last

#2 楼 @luikore 妙～

#2 楼 @luikore 帅气

都不错啊