HASH表可以实现。

好想法，我研究一下，多谢指教。

高人可以具体点么？给个代码学习一下呗

新手用九牛二虎之力才写出来的。供你见笑！
proc sql;
        create table d2 as
                select *,min(date) as date1 format=yymmdd10.
                        from d1
                        where fuxie=1
                        group by school
                        order by date
        ;
quit;
proc sql;
        create table d3 as
                select *,count(name) as count
                        from d2
                        group by school,name
                ;
quit;
data d4;
        set d3;
        by school;
        day=intck("day",date1,date)+1;
run;
proc sql;
        create table d5 as
                select distinct school,name,fuxie,date,count
                        from d4
                        where day lt 7
                union
                select school,name,fuxie,date,count
                        from d4
                        where day >7
        ;
quit;
data d6;
        set d5;
        by school;
        if first.school then fuxiecishu=1;
                else fuxiecishu+1;
run;
data d7;
        set d6;
        where fuxiecishu>=3 ;
        keep school fuxiecishu date;
run;