A= (from x in A
               let temp=A.SelectMany(a=>a.Split('|')).GroupBy(a=>a).Where(g=>g.Count()>1).Select(g=>g.Key)
               select temp.Any(q=>x.Contains(q))?x:x.Replace("|","")).ToArray();

------解决方案--------------------

探讨


还好我没有结贴，代码写的还是有一点问题，比如这样的3楼的代码就不行了，

string []A={ "标识", "日期|年度", "日期|季度", "日期|月度","商品|品名", "省区", "本期|销量", "本期|成本","上期|销量","上期|成本"};