这题怎么算呢?
set talk offclear
accept"请任意输入一串字符:"to p
l=len(p)
c=""
fori=1tol
A=substr(p,i,1)
do case
case asc(A)>=asc("a") and asc(A)<=asc("u") or asc(A)>=asc("a") and asc(A)<=asc("U")
a=chr(asc(a)+5)
case asc(A)>=asc("v") and asc(A)<=asc("z") or asc(A)>=asc("V") and asc (A)<=asc("Z")
A=chr(asc(a)-21)
endfor
?P+""+c
set talk on
那个朋友解释下。谢谢了