VB编程题答案.doc

（1）选择结构 （2）循环结构（3）数组 （4）过程1. 输入3个数，输出最大的数2. 有一元二次方程：aX2+bX+c=0，依次输入a，b，c，判断此方程是否有实根详细代码如下：Private Sub Command1_Click()Dim a As IntegerDim b As IntegerDim c As Integera = InputBox(a)b = InputBox(b)c = InputBox(c)If (b * b - 4 * a * c) = 0 ThenPrint Yes;ElsePrint NoEnd IfEnd Sub3. 输入一个百分制的成绩，若大于等于60，则用消息框弹出，显示“恭喜！成绩通过！”，若小于60，则弹出消息框，显示“抱歉！成绩没有通过！”4. 输入一年份，判断它是否为闰年，并显示有关信息。（判断闰年的条件是：年份能被4整除但不能被100整除，或者能被400整除）代码如下：Private Sub Command1_Click()Dim y%y = InputBox(请输入年数)If y Mod 4 = 0 And y Mod 100 0 Or y Mod 400 = 0 Then MsgBox (y & 年是闰年)Else MsgBox (y & 年是平年)End IfEnd Sub5. 输入学生的百分制成绩，转换输出为五级制成绩，90100分转换为优秀，8089转换为良好，7079转换为中等，6069转换为及格，060转换为不及格。代码如下：Private Sub Command1_Click() Dim n As Single Dim s As String n = Val(InputBox(请你输入成绩) Select Case n Case 90 To 100 s = 优秀 Case 80 To 90 s = 良 Case 70 To 80 s = 中 Case 60 To 70 s = 及格 Case 0 To 60 s = 不及格 Case Else s = 请你输入0至100自己的数字 End Select MsgBox sEnd Sub6. 随机产生一个三位正整数，然后逆序输出，产生的数与逆序数同时显示。例如，产生246，输出是642。代码如下：Private Sub Command1_Click()Dim n As IntegerDim a As StringDim b As String n = Int(Rnd * 900 + 100) a = Trim(Str(n) b = For I = 3 To 1 Step -1 b = b + Mid(a, I, 1)Next IText1.Text = aText2.Text = bEnd Sub7. 输入两个整数，求它们的最大公约数。Private Sub Command1_Click()Dim m As IntegerDim n As IntegerDim r As Integerm = InputBox(m)n = InputBox(n)r = m Mod nDo While r 0m = nn = rr = m Mod nLoopPrint n=; nEnd Sub8. 编程求200-400范围内5的倍数或7的倍数之和。(一个数如果同时是7和5的倍数，则只能加一次。Private Sub Command1_Click()Dim sum As Integersum = 0For i = 200 To 400If i Mod 5 = 0 Then sum = sum + iEnd IfIf i Mod 7 = 0 ThenEnd IfIf i Mod 5 = 0 And i Mod 7 = 0 Thensum = sum + iEnd IfNext iPrint sum=; sumEnd Sub9. 计算100300之间所有能被3和7整除的数之和代码如下：Private Sub Form_Click()For i = 100 To 300If i Mod 21 = 0 Thens = s + iEnd IfNext iPrint 和为; sEnd Sub10. 分别统计1-100中，满足3的倍数、7的倍数的数各有多少。代码如下：Private Sub Command1_Click()Dim count3 As IntegerDim count7 As Integercount3 = 0count7 = 0For i = 1 To 100 If i Mod 3 = 0 Then count3 = count3 + 1 End If If i Mod 7 = 0 Then count7 = count7 + 1 End IfNext iPrint count3=; count3Print count7=; count7 End Sub11. 某次歌曲大奖赛，有7个评委。如果分别输入7个评委对某个参赛者的打分数，按照去掉一个最高分和一个最低分的计算办法，求出该参赛者的平均得分。Private Sub Command1_Click()Dim mark As SingleDim aver As SingleDim max1 As SingleDim min1 As SingleFor i = 1 To 7 mark = InputBox( b ) If i = 1 Then max1 = mark: min1 = mark Else If mark max1 Then max1 = mark End If End If aver = aver + markNext iaver = (aver - max1 - min1) / 5Print averEnd Sub12. 输入一串字符，统计其中字母A(不区分大小写)出现的次数。Private Sub Command1_Click()Dim count As IntegerDim length As IntegerDim a As Stringa = Text1.Textlength = Len(a)count = 0For i = 1 To length If Mid(a, i, 1) = A Or Mid(a, i, 1) = a Then count = count + 1 End If Next i Text2.Text = count End Sub13. 我国目前有13亿人口，按人口年增长率0.8%计算，多少年后我国人口将超过26亿。Private Sub Command1_Click() Dim k, n Do Until k = 260000000 n = n + 1 k = 130000000 * (1 + 0.008) n Loop Print n & 年后人数为： & kEnd Sub14. 小猴有桃若干，第一天吃掉一半多一个；第二天吃剩下桃子的一半多一个；以后每天都吃尚存桃子的一半多一个，到第7天只剩一个，问小猴原有桃多少？ Private Sub Command1_Click() Dim a%, i% a = 1 For i = 1 To 6 a = 2 * (a + 1) Next i Print a End Sub代码如下：Private Sub Command1_Click()Dim result As Integerresult = 11For i = 1 To 7result = 2 * (result - 1)Next iPrint resultEnd Sub15. 求100以内的素数Private Sub Form_Click()Dim i%, j%For j = 2 To 100 For i = 2 To j - 1 If j Mod i Mod i = o Then Exit For Next i If i = j Then Print jNext jEnd Sub代码如下：Private Sub Command1_Click()For i = 1 To 100If IsSuShu(i) = True ThenPrint i;End IfNext iEnd SubPublic Function IsSuShu(ByVal n As Integer) As BooleanDim result As Booleanresult = TrueFor i = 2 To n - 1 If n Mod i = 0 Then result = False End IfNext i IsSuShu = result End Function16. 百元买百鸡问题。假定小鸡每只5角，公鸡每只2元，母鸡每只3元，编程求解购鸡方案。代码如下：Private Sub Command1_Click()For x = 1 To 100 For y = 1 To 100 For z = 1 To 100 If (x + y + z) = 100 And (0.5 * x + 2 * y + 3 * z) = 100 Then Print x, y, z End IfNext zNext yNext xEnd Sub17. 编程求斐波那契数列前11项。（斐波那契数列：F(0)=f(1)=1, F(n)=F(n-1)+F(n-2) n=2 ） 18. 将输入的字符串以反序显示，例如：输“ASDFGT”，显示“TGFDSA”Private Sub Form_Click()Dim a As StringDim b As IntegerDim c As StringDim n As Integera = InputBox()n = Len(a)For b = 1 To Int(n 2) c = Mid(a, b, 1) Mid(a, b, 1) = Mid(a, n - b + 1, 1) Mid(a, n - b + 1, 1) = cNext bPrint aEnd Sub19. 随机产生10个30,100内的整数，求最大值及所对应的下标Private Sub Form_Click()Dim a(1 To 10) As Integer, i%, maxa%, m%For i = 1 To 10a(i) = Int(Rnd * 70) + 30Next imaxa = a(1)For i = 2 To 10If a(i) a(1) Thenmaxa = a(i): m = iEnd IfNext iFor i = 1 To 10Print a(i);Next iPrint 最大值= & maxa; 它的下标为 & mEnd Sub20. 随机产生10个30,100内的整数，求最大值、最小值和平均值。代码如下：Private Sub Form_Click()Dim a(1 To 10) As Integer, amin, amax, i%, avera! For i = 1 To 10 a(i) = Int(Rnd * 71 + 30) Next i amin = a(1) amax = a(1) avera = a(1) For i = 2 To 10 If a(i) amax Then amax = a(i) If a(i) amin Then amin = a(i) avera = avera + a(i) Next i For i = 1 To 10 Print a(i); Next i Print Print max=; amax, min=; amin, avera=; avera / 10End Sub21. 随机产生10个30,100内的整数，求最小值及所对应的下标。 Private Sub Form_Click()Dim a(1 To 10) As Integer, i%, mina%, m%For i = 1 To 10 a(i) = Int(Rnd * 70) + 30Next imina = a(1)For i = 2 To 10 If a(i) a(1) Then mina = a(i): m = i ElseIf a(i) = a(1) Then mina = a(i): m = i End IfNext iFor i = 1 To 10 Print a(i);Next i Print 最小值为 & mina; 它的下标为 & mEnd Sub22. 随机生成一个整型的二维数组，范围在10,20之间，以下三角形式输出该数组。23. 随机产生10个1100的正整数放入数组，显示产生的数，求最大值、最小值、平均值。利用随机函数生成一个44的矩阵(即二维矩阵),范围是20,50内的整数,输出该矩阵所有数据之和代码如下：Private Sub Form_Click() Dim a%(3, 3) For I = 0 To 3 For j = 0 To 3 a(I, j) = Int(Rnd * 31 + 20) Print Tab(j * 5); a(I, j); Next j Next I s = a(0, 0) + a(1, 1) + a(2, 2) + a(3, 3) + a(3, 0) + a(2, 1) + a(1, 2) + a(0, 3) Print ; 和为; s;End Sub24.25. 已知有序数组a()，编程插入x（x的值为14）。数组a中的元素分别为12，6，4，89，75，63，100，20，31。26. 编写一函数，计算Double类型一维数组所有元素的平均值。代码如下：Private Function fsum (x() As Double ,n As Interger) As Double Dim I As Integer For i=1 to nfsum = fsum + x (i)Next ifsum = fsum / nEnd Function27. 用函数过程求表达式1+1/2+1/3+1/4+1/n的和.代码如下：Public Function sum(ByVal n As Integer) As Doubleresult = 0For I = 1 To n result =