21.輸入一個(gè)三位數(shù)的整數(shù),要求將此三位數(shù)的各位上的數(shù)字重新排列,組成一個(gè)盡可能大的三位數(shù).例如:輸入213,重新排列可得到盡可能大的三位數(shù)是321. 現(xiàn)要求編寫VB程序(運(yùn)行界面如圖所示),實(shí)現(xiàn)如下功能:在文本框Text1中輸入一個(gè)三位數(shù)整數(shù),單擊“求解”按鈕Command1,在文本框Text2中顯示重新組合后的最大三位數(shù)整數(shù).某同學(xué)按此要求編寫的程序如下,其中函數(shù)max(x)用于求解最大三位數(shù)整數(shù),但加框處代碼有錯(cuò),請(qǐng)改正. ①
②
Function max(x As Integer) As Integer Dim a As Integer,b As Integer,c As Integer,t As Integer a=x\100 b='① c=x mod 10 If a<b Then t=a:a=b:b=t If a<c Then t=a:a=c:c=t If b<c Then t=c:c=b:b=t max='② End Function Private Sub Command1_Click Dim n As Integer,y As Integer n=Val(Text1.Text) y=max(n) Text2.Text=Str(y) End Sub.
.(填:冒泡排序/選擇排序) (2)在程序①和②橫線處填入適當(dāng)?shù)恼Z句或表達(dá)式,把程序補(bǔ)充完整. Dim a(1To 10)As Integer Function f(x As Integer)As Boolean '代碼略 End Function Private Sub Command1_Click( ?。?br />Dim n As Integer'n用于統(tǒng)計(jì)已經(jīng)產(chǎn)生的隨機(jī)整數(shù)個(gè)數(shù) Dim i As integer,j As Integer Dim x As Integer,k As Integer Randomize'初始化Rnd函數(shù) n=0 List1.Clear'清除列表框中內(nèi)容 List2.Clear Do While n<10 x=lnt(Rnd*999)+1'產(chǎn)生[1,999]范圍內(nèi)的隨機(jī)整數(shù) If Not f(x) Then n=n+1 a(n)=x List1.AddItem Str(
) End If Loop For i=1To 9'進(jìn)行排序 For j=10To i+1
If a(j)<a(j-1)Then k=a(j):a(j)=a(j-1):a(j-1)=k End If Next j Next i For i=1To 10 List2.AddItem Str(a(i)) Next i End Sub.