VB中求a+aa+aaa+...（如2+22+222+2222+22222）前n项之和。大神们帮帮忙

ru ti

option base 1

dim a()

dim jia as long:dim i ,k

dim str,str1

dim and '和

for i=1 to len(text1.text)

str=mid(text1.text,i,1)

if str="+" then

jia=jia+1

end if

jia=jia+1

for i=1 to jia

for k=1 to i

str1=str1 & "2"

next k

a(i)=val(str1)

next i

for k=lbound(a) to ubound(a)

and=and+a(k)

next k

option base 1 dim a() dim jia as long:dim i ,k dim str,str1 dim and '和 for i=1 to len(text1.text) str=mid(text1.text,i,1) if str="+" then jia=jia+1 end if jia=jia+1 for i=1 to jia for k=1 to i str1=str1 & "2" next k a(i)=val(str1) next i for k=lbound(a) to ubound(a) and=and+a(k) next k 麻烦采纳，谢谢!