VB算法.docx

1、VB算法1. 若一元二次方程ax2+bx+c=0有两个实根，请编程计算方程的根。要求系数a,b,c用文本框从键盘上输入，方程的根用标签框输出。Private Sub Command1_Click()Dim a%, b%, c%a = Val(Text1.Text)b = Val(Text2.Text)c = Val(Text3.Text)If b 2 - 4 * a * c o Then MsgBox 无解, 5 ElseIf b 2 - 4 * a * c = 0 Then Text4 = Format(-b / 2 * a, 0.00) Text5 = Format(-b / 2 * a,

2、 0.00) Else Text4 = Format(-b + Sqr(b 2 - 4 * a * c) / 2 * a), 0.00) Text5 = Format(-b - Sqr(b 2 - 4 * a * c) / 2 * a), 0.00) End If End Sub2. 商品打折，购物300以上，95折；购物500以上，9折；购物1000以上，85折；购物5000以上，8折。请编程计算打折后的金额。Private Sub Command1_Click() Dim x!, y! x = Text1.Text If x 300 Then y = x ElseIf x 500 Then

3、 y = 0.95 * x ElseIf x 1000 Then y = 0.9 * x ElseIf x 5000 Then y = 0.85 * x Else y = 0.8 * x End If Text2.Text = y End Sub3. 判断某一年是否是闰年。Private Sub Form_Click()Dim y As Integery = InputBox(输入年数)If y Mod 400 = 0 Then End If Print y; 闰年4. 求s=1+2+3+100 和 t=1*2*3*10Private Sub Command1_Click()Dim s!, n

4、!s = 0n = 1For n = 1 To 100s = s + nn = n + 1Next nPrint sEnd SubPrivate Sub Command2_Click()Dim t!, i!t = 1i = 1For i = 1 To 10t = t * ii = i + 1Next iPrint tEnd Sub5. 用100元买100只兔子，雄兔5元1只，雌兔3元1只，幼兔1元3只，问各应买多少只？Private Sub Command1_Click()Dim x%, y%, z%For x = o To 20 For y = o To 33 z = 100 - x - y

5、If 5 * x + 3 * y + z / 3 * 1 = 100 ThenText1.Text = xText2.Text = yText3.Text = zEnd If NextNextEnd Sub求s=1-1/2+1/3-1/4+1/99-1/100 （各使用do while和for编程Private Sub Command1_Click()Dim s!, n!s = 1n = 2Do While n = 100s = s + (-1) (n - 1) * (1 / n)n = n + 1LoopText1.Text = sEnd SubPrivate Sub Command2_Cl

6、ick()Dim s!, n!s = 0For n = 1 To 100 s = s + (-1) (n - 1) * (1 / n)Next nText2.Text = sEnd Sub7. 在窗体上输出1-9和0的宝塔型图形，如图。Private Sub Form_Click()Dim i!For i = 1 To 9Print Tab(20 - i); String(2 * i - 1, Trim(Str(i)Next iEnd Sub9. 求100999中的水仙花数，如153=13+53+33。Private Sub Form_Click()Dim i!, x!, y!, z!For

7、i = 100 To 999 x = i Mod 10 y = (i Mod 100) 10 z = i 100If x 3 + y 3 + z 3 = z * 100 + y * 10 + x Then Print i End If Next i End Sub10. 利用Rnd函数产生10个099之间的整数，存放在数组中，求该数组中的最小值、最大值和平均值，然后在窗体上显示所有小于50的数组元素。Private Sub Command1_Click() Dim a(1 To 10) As Integer For i = 1 To 10 a(i) = Int(Rnd * 100) Pictu

8、re1.Print a(i) If a(i) 50 Then Picture2.Print a(i) End If Next Max = a(1) Min = a(1) aver = a(1) For i = 2 To 10 If Max a(i) Then Min = a(i) aver = aver + a(i) NextText1.Text = MaxText2.Text = MinText3.Text = aver / 10End Sub11. 利用Rnd函数产生10个099之间的随机数，从大到小排列，单击窗体后将原始数据和排序后的结果分别显示在窗体上。Private Sub Form

9、_Click()Dim d(9) As Integer Dim i%, j% Randomize Print Print Tab(5); 初始随机数为： Print Tab(5); For i = 0 To 9 d(i) = Int(Rnd * 100) Print d(i); Next For i = 0 To 8 For j = i + 1 To 9 If d(i) a(imin) Then imin = j Next j t = a(n) a(n) = a(imin) a(imin) = t Next n For n = 1 To 10 Print Print a(n);Next12.

10、利用Rnd函数产生10个100200之间的随机数放入一维数组中，然后将前5个元素和后5个元素对换，即第1个元素和第10个元素对换，第2个元素和第9个元素对换第5个元素和第6个元素对换，单击窗体后，分别输出数组原来各元素的值和对换后各元素的值。Dim i As Integer Dim a(1 To 10) As Integer Print Print Tab(5); 初始随机数为： Print Tab(5); For i = 1 To 10 Randomize a(i) = Rnd * 100 Print a(i); Next For n = 1 To 5 t = a(n) a(n) = a(1

11、0 - n + 1) a(10 - n + 1) = t Next Print Tab(5); 排序后为： Print Tab(5); For i = 1 To 10 Print a(i); Next13. 由用户输入两个整数，求这两个整数的最大公约数。（使用Inputbox进行输入）Private Sub Command1_Click() Dim m%, n%, r% m = InputBox(请输入一个数) n = InputBox(请输入一个数) If m n Then t = m m = n n = t r = m Mod n End If Do While r 0 m = n n =

12、 r r = m Mod n Loop Text3.Text = n End Sub14. 分别计算y=(5!+7!) / 3! 和s=1！+2！+10！的值。（使用函数子程序进行编程）Public Function jax(n%) As DoubleDim t As DoubleDim i As Doublet = 1For i = 1 To n t = t * i Nextjax = tEnd FunctionPrivate Sub Command1_Click()Text1.Text = (jax(5) + jax(7) / jax(3)End SubPrivate Sub Comman

13、d2_Click()Dim s As Double Dim n As Integer s = 0 For n = 1 To 10 s = s + jax(n) NextText2.Text = sEnd Sub16. 利用inputbox输入一个正整数，并判断其是否为素数。Private Sub Form_Click()Dim x!, i!x = InputBox(请输入一个数)For i = 2 To x - 1 If x Mod i = 0 Then F = 1 Exit For End IfNext iIf F = 1 Then Label1.Caption = 你输入的数是 & x &

14、 ，该数不是素数。Else Label1.Caption = 你输入的数是 & x & ，该数是素数。End IfEnd Sub2. 设计文本编辑器应用程序1A2.vbp。界面如图1-1-2所示。其中，“文件”菜单中有2个子菜单“输入”和“退出”；“字体外观”菜单中有3个子菜单“粗体”、“斜体”和“下划线”；“字体名称”菜单中有3个子菜单“宋体”、“华文行楷”和“隶书”；“字体大小”菜单有4个子菜单“12”、“18”、“24”和“28”。rivate Sub cuti_Click() = Not End SubPrivate Sub h_Click() = 华文行楷End SubPrivate

15、 Sub l_Click() = 隶书End SubPrivate Sub s_Click() = 宋体End SubPrivate Sub shuru_Click()List1.AddItem 大学计算机基础End SubPrivate Sub tuichu_Click()List1.ClearEnd SubPrivate Sub xiahuaxian_Click() = Not End SubPrivate Sub xieti_Click() = Not End SubPrivate Sub z_Click() = 12End Sub4Private Sub Command1_Click() Dim x As Integer x = Text1.Text If Option1.Value = True Then Text2.Text = Sin(x * 3.14 / 180) End If If Option2.Value = True Then Text2.Text = Cos(x * 3.14 / 180) End If If Option3.Value = True Then Text2.Text = Tan(x * 3.14 / 180) End IfEnd Sub