電腦軟體設計練習卷(共10回)

電腦軟體設計練習卷(共10回)答案

精進練習題(答案)

1.輸入n，求1到n之間質數的個數，最大的質數為何？

Dim n, s, cnt As Long

Console.Write("請輸入一數n，求1到n之間最大質數=")

n = Console.ReadLine

For i = 1 To n

    For j = 1 To i

If i Mod j = 0 Then cnt = cnt + 1

    Next

    If cnt = 2 Then s = i

    cnt = 0

Next

Console.WriteLine("最大質數為" & s)

2.魔術矩陣：設計一個奇數行列的矩陣，每一行、每一列與斜線的和均為相同。

 例如：8  1  6

       3  5  7

       4  9  2

        Dim intSI, intSJ, intI, intJ, intK, intT, iX, iY, Num(,), N As Integer

        Do

            Console.Write("輸入一個奇數:")

            N = Val(Console.ReadLine())

        Loop While (N And 1) = 0

        ReDim Num(N - 1, N - 1)

        intSI = (N - 1) / 2

        intSJ = -intSI

        For intT = 0 To N - 1

            intI = intSI

            intJ = intSJ

            For intK = 1 To N

                iX = IIf(intI < 0, N + intI, IIf(intI >= N, intI - N, intI))

                iY = IIf(intJ < 0, N + intJ, IIf(intJ >= N, intJ - N, intJ))

                Num(iX, iY) = intT * N + intK

                intI = intI + 1

                intJ = intJ + 1

            Next

            intSI = intSI - 1

            intSJ = intSJ + 1

        Next

        For iY = N - 1 To 0 Step -1

            For iX = 0 To N - 1

                Console.Write(Num(iX, iY) & vbTab)

            Next

            Console.WriteLine()

        Next

        Console.ReadKey()

3.將10位數字轉換為N進位數。

Dim n, a, d As Integer, q As String

Console.Write("請輸入一數=")

a = Console.ReadLine

Console.Write("將數字轉換成N進位數(N<10)，N=")

n = Console.ReadLine

d = a

Do While d > 0

    q = (d Mod n) & q

    d = d \ n

Loop

Console.WriteLine("結果=" & q)

4.利用輾轉相除法，求二數的最大公因數。

　（輸入二數a,b，假如b>a，則二者交換，a除以b之後得餘數r，若餘數不為0，則以除　數設定為被除數，餘數設定為除數，之後重複執行）

　　If b > a then temp=a : a=b : b=temp

    Do

       r = a Mod b : a=b : b=r

    Loop While r>0

Dim a, b, temp, r As Integer

Console.WriteLine("請輸入2數利用輾轉相除法求最大公因數")

Console.Write("請輸入A=")

a = Console.ReadLine

Console.Write("請輸入B=")

b = Console.ReadLine

If b > a Then temp = a : a = b : b = temp

Do

    r = a Mod b : a = b : b = r

Loop While r > 0

Console.WriteLine("最大公因數=" & a)

5.輸入三角形三邊長，判斷三角形為正三角形、鈍角三角形、銳角三角形、直角三角形。

Dim a, b, c As Single, s As String

Console.WriteLine("請輸入三角形三邊長ABC")

Console.Write("請輸入A=")

a = Console.ReadLine

Console.Write("請輸入B=")

b = Console.ReadLine

Console.Write("請輸入C=")

c = Console.ReadLine

If a + b > c And b + c > a And a + c > b Then

    If a = b And b = c Then

s = s & "正三角形"

    ElseIf (a ^ 2 + b ^ 2 = c ^ 2) Or (a ^ 2 + c ^ 2 = b ^ 2) Or (c ^ 2 + b ^ 2 = a ^ 2) Then

s = s & "直角三角形"

    ElseIf (a ^ 2 + b ^ 2 > c ^ 2) Or (a ^ 2 + c ^ 2 > b ^ 2) Or (c ^ 2 + b ^ 2 > a ^ 2) Then

s = s & "鈍角三角形"

    ElseIf (a ^ 2 + b ^ 2 < c ^ 2) Or (a ^ 2 + c ^ 2 < b ^ 2) Or (c ^ 2 + b ^ 2 < a ^ 2) Then

s = s & "銳角三角形"

    End If

Else

    s = "不是三角形"

End If

Console.WriteLine("三角形為" & s)

6.迴文判斷：輸入一字串，檢查是否為迴文(例如:ABCDCBA是迴文，123456不是)

Dim a As String

Console.WriteLine("請輸入一字串判斷是否為迴文")

Console.Write("請輸入字串:")

a = Console.ReadLine()

If a = StrReverse(a) Then

    Console.WriteLine("輸入字串為迴文")

Else

    Console.WriteLine("輸入字串不是迴文")

End If

7.排序：請輸入3個數，請由小到大排序這三個數字。

Dim a(3), temp As Single

Console.WriteLine("請輸入3個數字由小到大排列")

Console.Write("請輸入數字一:")

a(1) = Val(Console.ReadLine)

Console.Write("請輸入數字二:")

a(2) = Val(Console.ReadLine)

Console.Write("請輸入數字三:")

a(3) = Val(Console.ReadLine)

For i = 1 To 2

    For j = i To 3

If a(j) < a(i) Then temp = a(j) : a(j) = a(i) : a(i) = temp

    Next

Next

Console.WriteLine("結果為=" & a(1) & " " & a(2) & " " & a(3))

8.輸入正整數 N，請將 N 的所有正因數由小到大印出來。

Dim n As Long, s As String

Console.WriteLine("請輸入一數N,將N的所有正因數由小到大印出來")

Console.Write("N=")

n = Console.ReadLine

For i = 1 To n

    If n Mod i = 0 Then s = s & " " & i

Next

Console.WriteLine("結果=" & s)

9.輸入正整數 N，請將N轉成二進位輸出。

Dim  a, d As Integer, q As String

Console.Write("將數字轉換成2進位數")

Console.Write("請輸入一數=")

a = Console.ReadLine

d = a

Do While d > 0

    q = (d Mod 2) & q

    d = d \ 2

Loop

Console.WriteLine("結果=" & q)

10.寫出ABCDE-WXYZ=66666的程式碼，其中ABCDEWXYZ為1-9不同的數字，找出所有ABCDE與WXYZ的組合

        Dim a(9), t As String, b, c As Integer

        c = 1000

        For b = 66666 To 99999

            Do While c < 9999

                If b - c = 66666 Then

                    t = Trim(Str(b)) & Trim(Str(c))

                    For i = 1 To 9

                        a(i) = Mid(t, i, 1)

                    Next

                    For i = 1 To 8

                        For j = 2 To 9

                            If a(i) = a(j) Then Exit Do

                        Next

                    Next

                    Console.WriteLine(b & "-" & c & "=66666")

                End If

                c = c + 1

            Loop

        Next

11.請印出九九乘法表

For i = 1 To 9

    For j = 1 To 9

        Console.Write(i & "X" & j & "=" & i * j & " ")

    Next

    Console.WriteLine()

Next

12.計算輸入的年份是否為閏年，閏年的條件為：

    可被 1000 整除。

    可被 400 整除。

    可被 4 整除。

    不可被 100 整除。

    口訣：逢四百年或千年閏，逢百年不閏，逢四年又閏。

       Dim a As Integer

        Console.Write("閏年判斷，請輸入年份=")

        a = Val(Console.ReadLine())

        If a Mod 400 = 0 Then

            Console.WriteLine(a & "年是閏年")

        ElseIf a Mod 4 = 0 And a Mod 100 <> 0 Then

            Console.WriteLine(a & "年是閏年")

        Else

            Console.WriteLine(a & "年不是閏年")

        End If