第三讲习题答案.docx

1、第三讲习题答案第三讲习题答案1. 从键盘输入三个数，判断它们能否构成三角形的三个边。如果能构成一个三角形，则计算三角形的面积，否则给出相应信息。Private Sub Command1_Click() Dim a As Integer Dim b As Integer Dim c As Integer Dim s As Single Dim area As Single a = InputBox(请输入第一条边的长度:) b = InputBox(请输入第二条边的长度:) c = InputBox(请输入第三条边的长度:) If (a + b c) And (a + c b) And (b +

2、 c a) Then s = (a + b + c) / 2 area = Sqr(s - a) * (s - b) * (s - c) MsgBox 能构成三角形 & Chr(13) & Chr(10) & 三角形面积是: & area Else MsgBox 不能构成三角形 End IfEnd Sub2. 编写程序，任意输入一个整数，判定该整数奇偶性。 Private Sub Command1_Click() Dim n As Integer n = InputBox(输入一个整数) If n Mod 2 = 0 Then Print 是偶数 Else Print 是奇数 End IfEn

3、d Sub3. 求一元二次方程的a*x2+b*x+c=0根. Private Sub Command1_Click() Dim a As Single Dim b As Single Dim c As Single Dim delta As Single Dim x1 As Single Dim x2 As Single a = InputBox(输入方程系数a:) b = InputBox(输入方程系数b:) c = InputBox(输入方程系数c:) delta = b * b - 4 * a * c If delta = 0 Then x1 = (-b + Sqr(delta) / (

4、2 * a) x2 = (-b - Sqr(delta) / (2 * a) MsgBox 方程的根为: & x1 & 和 & x2 Else MsgBox 方程没有根 End IfEnd Sub4. 编程求出S=1+（1+2）+（1+2+3）+（1+2+3+4+N）的值 （N的值由键盘输入）。Private Sub Command1_Click() Dim n As Integer Dim s As Long Dim i As Integer Dim p As Long n = InputBox(请输入N的值:) s = 0 p = 0 For i = 1 To n p = p + i s

5、= s + p Next MsgBox 和: & sEnd Sub5. 编写程序，输出100300间的所有素数。 Private Sub Command1_Click() Dim i As Integer Dim j As Integer Dim flag As Integer Dim line As Integer line = 1 For i = 100 To 300 flag = 1 For j = 2 To Sqr(i) If i Mod j = 0 Then flag = 0 Exit For End If Next j If flag = 1 Then Print i; ; If

6、line = 5 Then line = 0 Print End If line = line + 1 End If Next iEnd Sub6. 编写程序，求解鸡兔同笼问题。一个笼子中有鸡X只，兔Y只，每只鸡有2只脚，每只兔有4只脚。今知鸡和兔的总头数为H，总脚数为F。问笼中鸡和兔各若干？ （H，F的值由键盘输入）Private Sub Command1_Click() Dim h As Integer Dim f As Integer Dim x As Integer Dim y As Integer h = Val(Text1.Text) f = Val(Text2.Text) For

7、 x = 1 To h y = h - x If 2 * x + 4 * y = f Then Text3.Text = x Text4.Text = y Exit For End If Next xEnd SubPrivate Sub Form_Load() Text1.Text = Text2.Text = Text3.Text = Text4.Text = End Sub7. 勾股定理中3个数的关系是：a2+b2=c2。编写程序，输出30以内满足上述关系的整数组合，例如3、4、5就是一个整数组合。 Private Sub Command1_Click() Dim a As Integer

8、 Dim b As Integer Dim c As Integer For a = 1 To 30 For b = 1 To 30 For c = 1 To 30 If (a * a + b * b = c * c) And (b a) Then Print a, b, c End If Next c Next b Next aEnd Sub8. 从键盘上输入10个整数，并放入一个一维数组中，然后将其前5个元素与后5个元素对换，即第1个元素与第10个元素互换，第2个元素与第9个元素互换第5个元素与第6个元素互换，。分别输出数组原来的各元素的值和对换后各元素的值。 Private Sub Co

9、mmand1_Click() Dim i As Integer Dim a(10) As Integer Dim temp As Integer For i = 1 To 10 a(i) = InputBox(请输入第 & i & 数) Next i For i = 1 To 10 Print a(i); ; Next i Print For i = 1 To 5 temp = a(i) a(i) = a(11 - i) a(11 - i) = temp Next i For i = 1 To 10 Print a(i); ; Next iEnd Sub9. 编程计算某学生奖学金的等级，以三门

10、课成绩(用户输入)为依据，评定标准如下：(1)一等奖，符合下列条件之一：(a)平均分大于95(b)有两门课100分，第三门课不低于80分(2)二等奖，符合下列条件之一：(a)平均分大于90分(b)有一门课100分，其他课程不低于75分(3)三等奖，各门课成绩均不低于70分Private Sub Command1_Click() Dim cj1 As Integer Dim cj2 As Integer Dim cj3 As Integer Dim avecj As Single cj1 = Val(Text1.Text) cj2 = Val(Text2.Text) cj3 = Val(Text

11、3.Text) avecj = (cj1 + cj2 + cj3) / 3 If (avecj 95) Or (cj1 = 100 And cj2 = 100 And cj3 = 80) Or (cj1 = 100 And cj3 = 100 And cj2 = 80) Or (cj3 = 100 And cj2 = 100 And cj1 = 80) Then Text4.Text = 一等奖 ElseIf (avecj 90) Or (cj1 = 100 And cj2 = 75 And cj3 = 75) Or (cj1 = 100 And cj3 = 75 And cj2 = 75)

12、Or (cj3 = 100 And cj2 = 75 And cj1 = 75) Then Text4.Text = 二等奖 ElseIf (cj1 = 70 And cj2 = 70 And cj3 = 70) Then Text4.Text = 三等奖 End IfEnd SubPrivate Sub Form_Load() Text1.Text = Text2.Text = Text3.Text = Text4.Text = End Sub10. 从键盘上输入10个无序数，去掉一个最大数和最小数，然后求其平均值。Private Sub Command1_Click() Dim i As

13、Integer Dim max As Integer Dim min As Integer Dim ave As Single Dim sum As Integer Dim a(10) As Integer For i = 1 To 10 a(i) = InputBox( 请输入第 & i & 个数) Next sum = a(1) max = a(1) min = a(1) For i = 2 To 10 If max a(i) Then min = a(i) sum = sum + a(i) Next i sum = sum - max - min ave = sum / 8 MsgBox

14、 平均值为: & aveEnd Sub11. 求下面第n个Fibonacel数，Fibonacel数定义如下：a) f(0)=0b) f(1)=1c) f(n)=f(n-1)+f(n-2) n=2Private Sub Command1_Click() Dim f() As Integer Dim i As Integer Dim n As Integer n = InputBox(请输入要输出多少项) ReDim f(n) f(0) = 0 f(1) = 1 For i = 2 To n - 1 f(i) = f(i - 1) + f(i - 2) Next i For i = 0 To n

15、 - 1 Print f(i); ; If (i + 1) Mod 5 = 0 Then Print Next iEnd Sub12. 100匹马驮100担货，大马一匹驮3担，中马一匹驮2担，小 马2匹驮一担，编程计算大、中、小马的数量。Private Sub Command1_Click() Dim bigh As Integer Dim midh As Integer Dim smallh As Integer For bigh = 1 To 33 For midh = 1 To 50 smallh = 100 - bigh - midh If bigh * 3 + midh * 2 +

16、smallh * 0.5 = 100 Then Print bigh, midh, smallh End If Next midh Next bighEnd Sub13. 有36块砖，共36人搬，男人一次搬4砖，女人一次搬3砖，小孩一次两人搬一块，求一次搬完且不可以空手，问男人，女人和小孩各需多少人？Private Sub Command1_Click() Dim man As Integer Dim woman As Integer Dim child As Integer For man = 1 To 9 For woman = 1 To 12 child = 36 - man - wom

17、an If man * 4 + woman * 3 + child * 0.5 = 36 Then Print man, woman, child End If Next woman Next manEnd Sub14. 编写猜数游戏程序，由计算机自动产生一个1,100的随机整数，用户输入猜数后由计算机自动比较，并通过消息框提示太大了或太小了等信息，共有5次猜数机会，如果在规定的次数内猜中，则消息框中显示猜中了等信息，如果5次都不对，则显示猜数失败等信息。Private Sub Command1_Click() Dim computer As Integer Dim user As Integ

18、er Dim i As Integer Randomize computer = Int(Rnd * 100) + 1 For i = 1 To 5 user = InputBox(请输入你猜的数) If user = computer Then MsgBox 你猜对了 Exit For Else If user computer Then MsgBox 猜错了,太大了,还有 & (5 - i) & 次机会 Else MsgBox 猜错了,太小了,还有 & (5 - i) & 次机会 End If End If Next i If i 5 Then MsgBox 猜数失败 End IfEnd

19、Sub15. 编程完成，从一堆一分，二分，五分的硬币中取出20枚，使其总值为60分，要求输出有多少种取法，及每一种取法的一分，二分，五分的个数.Private Sub Command1_Click() Dim yf As Integer 表示一分 Dim ef As Integer 表示二分 Dim wf As Integer 表示五分 Dim coun As Integer coun = 0 计数器 Print 一分, 二分, 五分 For yf = 1 To 20 For ef = 1 To 20 wf = 20 - yf - ef If yf + ef * 2 + wf * 5 = 60

20、 Then Print yf, ef, wf coun = coun + 1 End If Next ef Next yf Print 一共有 & coun & 种取法End Sub16. 随机生成20个100以内的正整数，将其中的奇数和偶数分两行显示在窗体上。Private Sub Command1_Click() Dim a(20) As Integer Dim i As Integer Randomize For i = 1 To 20 a(i) = Int(Rnd * 100) Next i 处理奇数 For i = 1 To 20 If a(i) Mod 2 = 1 Then Pri

21、nt a(i); ; Next i Print 处理偶数 For i = 1 To 20 If a(i) Mod 2 = 0 Then Print a(i); ; Next iEnd Sub17. 产生10个100以内的随机整数，将它们从大到小排序输出Private Sub Command1_Click() Dim i As Integer, j As Integer Dim a(10) As Integer Dim pos As Integer Dim temp As Integer Randomize For i = 1 To 10 a(i) = Int(Rnd * 100) 生成10个随

22、机数，并输出 Print a(i); ; Next i Print For i = 1 To 9 pos = i For j = i + 1 To 10 If a(pos) a(j) Then pos = j 找到最大数的位置，记录在pos中 Next j If pos i Then 交换最大数和当前第一个数的位置 temp = a(i) a(i) = a(pos) a(pos) = temp End If Next i For i = 1 To 10 Print a(i); ; 将结果输出显示 Next iEnd Sub18. 产生10个100以内的随机整数，求它们的和及平均值Private

23、 Sub Command1_Click() Dim i As Integer Dim a(10) As Integer Dim sum As Integer Dim ave As Single Randomize For i = 1 To 10 a(i) = Int(Rnd * 100) 生成10个随机数，并输出 Print a(i); ; Next i For i = 1 To 10 sum = sum + a(i) Next i ave = sum / 10 Print Print 和为: & sum Print 平均值: & aveEnd Sub19. 产生10个100以内的随机整数，求

24、它们的最大值和最小值Private Sub Command1_Click() Dim i As Integer Dim a(10) As Integer Dim max As Integer Dim min As Integer Randomize For i = 1 To 10 a(i) = Int(Rnd * 100) 生成10个随机数，并输出 Print a(i); ; Next i max = a(1) min = a(1) For i = 1 To 10 If max a(i) Then min = a(i) Next i Print Print 最大值: & max Print 最

25、小值: & minEnd Sub20. 产生10个100以内的随机整数，去掉一个最大值，去掉一个最小值，求平均值Private Sub Command1_Click() Dim i As Integer Dim max As Integer Dim min As Integer Dim ave As Single Dim sum As Integer Dim a(10) As Integer Randomize For i = 1 To 10 a(i) = Int(Rnd * 100) Print a(i); ; Next sum = a(1) max = a(1) min = a(1) Fo

26、r i = 2 To 10 If max a(i) Then min = a(i) sum = sum + a(i) Next i sum = sum - max - min ave = sum / 8 Print Print 平均值为: & aveEnd Sub21. 产生10个100以内的随机整数，统计其中偶数有多少个Private Sub Command1_Click() Dim a(10) As Integer Dim i As Integer Dim coun As Integer Randomize For i = 1 To 10 a(i) = Int(Rnd * 100) Pri

27、nt a(i); ; Next coun = 0 For i = 1 To 10 If a(i) Mod 2 = 0 Then coun = coun + 1 Next i Print Print 有 & coun & 个偶数End Sub22. 打印出所有的“水仙花数”，所谓“水仙花数”是指一个三位数，其各位数字立方和等于该数本身。例如：153是一个“水仙花数”，因为153=1的三次方5的三次方3的三次方。Private Sub Command1_Click()方法一Dim i As IntegerDim s As StringDim a As IntegerDim b As Integer

28、Dim c As IntegerFor i = 100 To 999 s = LTrim(Str(i) a = Val(Left(s, 1) b = Val(Mid(s, 2, 1) c = Val(Right(s, 1) If a 3 + b 3 + c 3 = i Then Print i End IfNext iEnd SubPrivate Sub Command2_Click()方法二Dim i As IntegerDim s As StringDim a As IntegerDim b As IntegerDim c As IntegerFor i = 100 To 999 a =

29、i Mod 10 b = i 100 c = (i 10) Mod 10 If a 3 + b 3 + c 3 = i Then Print i End IfNext iEnd Sub23. 输入二个整数，计算它们的最大公约数和最小公倍数Private Sub Command1_Click() Dim m As Integer Dim n As Integer Dim d As Integer Dim m1 As Integer Dim n1 As Integer m = InputBox(请输入第一个数) n = InputBox(请输入第二个数) m1 = m n1 = n If m n Then d = m m = n