1021

        '14. 輸入西元年 y,判斷 y 是「閏年」還是「平年」?
        'p14. 輸入西元年 y,
        Dim y As Integer
        Dim ans As String = ""
        y = InputBox("西元年 = ", "輸入西元年 y,判斷 y 是「閏年」還是「平年」", 0)
        '判斷 y 是「閏年」還是「平年」?
        If (y Mod 400 = 0) Or (y Mod 4 = 0 And y Mod 100 <> 0) Then
            ans = y & "是閏年"
        Else
            ans = y & "是平年"
        End If
        Me.TextBox1.Text = ans

        '16. 輸入 a, b, c 三個邊長,判斷是否能構成三角形? 若能構成三角形,則計算此三角形面積。
        '16. 輸入 a, b, c 三個邊長
        Dim a, b, c As Single
        Dim ans As String = ""
        a = InputBox("a =", "判斷是否能構成三角形?", 0)
        b = InputBox("b =", "判斷是否能構成三角形?", 0)
        c = InputBox("c =", "判斷是否能構成三角形?", 0)
        '判斷是否能構成三角形?
        If a + b > c And a + c > b And b + c > a Then
            Dim s As Single = (a + b + c) / 2
            ans = "三角形面積 = " & (s * (s - a) * (s - b) * (s - c)) ^ 0.5
        Else
            ans = "不是三角形"
        End If
        Me.TextBox2.Text = ans

        '輸入初值、終值、增量,印出迴圈控制變數值的 印出迴圈控制變數值的變化和執行次數()
        Dim _start, _stop, _step '初值、終值、增量
        _start = InputBox("_start =", "印出迴圈控制變數值的變化和執行次數")
        _stop = InputBox("_stop =", "印出迴圈控制變數值的變化和執行次數")
        _step = InputBox("_step =", "印出迴圈控制變數值的變化和執行次數")
        Dim ans = "For i = " & _start & " To " & _stop & " Step " & _step & vbNewLine & _
                  "Next" & vbNewLine & _
                  "迴圈內 i = " & vbNewLine
        Dim cnt = 0 'counter 計數器
        For i = _start To _stop Step _step
            cnt += 1
            ans &= i & ","
        Next
        Me.TextBox5.Text = ans & vbNewLine & "====For...Next迴圈執行" & cnt & "次===="

        '18. 解二方一次方程式 ax + by = m
        '                     cx + dy = n 。輸入數值 a, b, m, c, d, n,則:
        Dim a, b, m, c, d, n As Integer
        Dim ans = ""
        a = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                             cx + dy = n" & vbNewLine & _
                     "a = ", "二方一次方程式", 1)
        b = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                    cx + dy = n" & vbNewLine & _
                     "b = ", "二方一次方程式", 1)
        m = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                    cx + dy = n" & vbNewLine & _
                     "m = ", "二方一次方程式", 1)
        c = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                    cx + dy = n" & vbNewLine & _
                     "c = ", "二方一次方程式", 1)
        d = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                    cx + dy = n" & vbNewLine & _
                     "d = ", "二方一次方程式", 1)
        n = InputBox("二方一次方程式 ax + by = m " & vbNewLine & _
                     "                    cx + dy = n" & vbNewLine & _
                     "n = ", "二方一次方程式", 1)
        If a * d - b * c <> 0 Then
            ans &= "x = " & (m * d - n * b) / (a * d - b * c)
            ans &= " , y = " & (a * n - c * m) / (a * d - b * c)
        ElseIf b * n - m * d <> 0 Then
            ans = "無解"
        Else
            ans = "無限多組解"
        End If
        Me.TextBox6.Text = ans