Z2A_VB_寒輔練習之一

參考解
   Function M4P12(ByVal s As String) As String
        ' M4P12_N!尾數的0
        Dim x As Integer = s
        Dim cnt As Integer = 0
        For i = 5 To x Step 5
            Dim k As Integer = i
            Do While k Mod 5 = 0  ' 5的次方數會被整除多次
                cnt += 1
                k \= 5
            Loop
        Next
        Return cnt '1~x 共被5整除幾次就有幾個 尾數0
    End Function

    Function M4P21(ByVal s As String) As String
        ' M4P21_計程車費率計算
        Dim x As Integer = s * 1000 - 1500  '扣掉起跳 1500公尺
        Dim ans As Integer = 85 '起跳 85元
        If x < 0 Then Return ans '小於1500公尺只收 85
        ans += 5 * (x \ 250)
        If x Mod 250 <> 0 Then ans += 5
        Return ans ' 超過1500公尺的 \250每單位5元，餘數不為0再+5元
    End Function

    Function M4P22(ByVal s As String) As String
        ' M4P22_迴文
        Dim n As Integer = s.Length '字串長度
        Dim m As Integer = n \ 2  '字串長度的一半
        '由第1字與最後1字比，第2字與倒數第2字比， … 第m字與倒數第m字比
        For i = 1 To m
            If Mid(s, i, 1) <> Mid(s, n - i + 1, 1) Then Return "N"
        Next
        Return "Y" ' 皆沒有不同，即是迴文
    End Function

 Private Sub Button4_Click( . . .) Handles Button4.Click
        ' F4P11_電梯電費計算系統 ，輸入有兩列，以兩個文字方塊讀入s1,s2
        Dim s1 As String = TextBox1.Text '例：7
        Dim s2 As String = TextBox2.Text '例：2,9,7,3,4,6,1
        Label1.Text = F4P11(s1, s2)

    End Sub
  Function F4P11(ByVal s1 As String, ByVal s2 As String) As String
        ' F4P11_電梯電費計算系統
        Dim x As Integer = s1 '共停過x個樓層
        Dim dat() = s2.Split(",")  '有哪幾層以，號隔開：split切好分成dat(0)~dat(x-1)
        Dim ans As Integer = 0
        For i = 1 To x - 1
            Dim f As Integer = dat(i)
            If f > dat(i - 1) Then
                ans += 20 * (f - dat(i - 1))
            Else
                ans += 10 * (dat(i - 1) - f)
            End If
        Next
        Return ans
    End Function

    Function F4P22(ByVal s As String) As String
        ' F4P22_最大公約數計算
        Dim dat() = s.Split(",") ' '共有以，號隔開不一定幾個[假設m個]的數字：split切好分成dat(0)~dat(m-1)
        Dim m As Integer = dat.Length
        Dim ans As Integer = dat(0)
        For i = 1 To m - 1
            ans = gcd(ans, dat(i))
        Next
        Return ans
    End Function
    Function gcd(ByVal a As Integer, ByVal b As Integer) As Integer
        '求兩個非0正整數a,b的最大公約數, 運算後 更新後的 b即是
        Dim r As Integer = a Mod b
        Do Until r = 0
            a = b
            b = r
            r = a Mod b
        Loop
        Return b
    End Function
   

    Function F4P31(ByVal s As String) As String
        ' F4P31_計算位元為1的個數
        Dim x As Integer = s
        Dim cnt As Integer = 0  '位元1有幾個
        Do Until x = 0
            cnt += x Mod 2
            x \= 2
        Loop
        Return cnt ' 除2的餘數為1 加入 cnt
    End Function

    Function M5P42(ByVal s As String) As String
        ' M5P42_十進制數轉二進制數
        Dim dat() = s.Split(",")
        dat(0) = StrReverse(dat(0))  ' 或 Strings.StrReverse 將字串內容反轉
        dat(1) = StrReverse(dat(1))
        Dim x As Integer = dat(0), y As Integer = dat(1)
        Dim sum As Integer = StrReverse(x + y)
        Dim ans As String = ""
        ' 以下將 sum轉為 二進制，每除2一次的餘數串在前面
        Do While sum <> 0
            ans = sum Mod 2 & ans
            sum \= 2
        Loop
        Return ans

    End Function