努力学习C++

          已知两个数字为1~30的，甲知道两数只和，乙知道两数之积，甲问乙：“你知道是那两个数吗？”乙说：“不知道”。乙问甲：“你知道是那两个数吗？”甲说：“也不知道”。于是，乙说 ：“那我知道了”随后甲也说：“那我也知道了”这两个数是'什么？

以下用VB。NET实现：

    Dim NUM, SUM, PRODUCT As Int32
    Dim Product1()() As Int32
    Dim i, m, n, Sum1(3)() As Int32

    Private Sub MyMain()
        Product1 = Nothing
        NUM = CInt(Me.TextBox1.Text)
        GetSum1()
        GetProduct1()
        For m = 1 To NUM
            For n = m To NUM
                If SumOnly(m, n) Or ProductOnly(m, n) Then GoTo NextItem '不好意思用了个ＧＯＴＯ
                SUM = m + n
                PRODUCT = m * n
                '甲的和产生的积中最多有（n -2）个是唯一积
                If SUMtoPRODUCT_N_2(SUM) < 2 Then GoTo NextItem
                '乙的积产生的和中有且只有一个满足1、不是唯一和 2、和产生的积中最多有（n -2）个是唯一积
                '并且其余的和均满足 1、不是唯一和 2、有n－1个唯一积
                If PROCUCTtoSUM(PRODUCT) Then
                    MsgBox(m.ToString() & "  " & n.ToString())
                End If
NextItem:   Next

        Next

    End Sub
    Private Sub GetSum1()
        '产生唯一和并保存在数组中
        ReDim Sum1(0)(1)
        Sum1(0)(0) = 1
        Sum1(0)(1) = 1
        ReDim Sum1(1)(1)
        Sum1(1)(0) = 1
        Sum1(1)(1) = 2
        ReDim Sum1(2)(1)
        Sum1(2)(0) = NUM - 1
        Sum1(2)(1) = NUM
        ReDim Sum1(3)(1)
        Sum1(3)(0) = NUM
        Sum1(3)(1) = NUM
    End Sub
    Private Function SumOnly(ByVal N1 As Int32, ByVal N2 As Int32) As Boolean
        '判断是否为唯一和
        Dim i As Int32
        For i = 0 To 3
            If N1 = Sum1(i)(0) AndAlso N2 = Sum1(i)(1) Then Return True
        Next
        Return False
    End Function
    Private Sub GetProduct1()
        '产生唯一积并保存在数组中
        Dim tmp(NUM * NUM)() As Int32
        For m = 1 To NUM '????????????????
            For n = m To NUM  '??????????????
                Dim meme() As Int32 = tmp(m * n)
                If meme Is Nothing Then
                    ReDim meme(2)
                Else
                    ReDim Preserve meme(meme.Length + 1)
                End If

                meme(meme.Length - 1) = m
                meme(meme.Length - 2) = n
                meme(0) += 1
                tmp(m * n) = meme
                meme = Nothing
            Next
        Next
        For i = 1 To NUM * NUM
            If Not tmp(i) Is Nothing AndAlso tmp(i)(0) = 1 Then
                For m = 1 To tmp(i).GetUpperBound(0) Step 2
                    If Product1 Is Nothing Then
                        ReDim Product1(0)
                        ReDim Product1(0)(1)
                    Else
                        ReDim Preserve Product1(Product1.Length)
                        ReDim Product1(Product1.Length - 1)(1)
                    End If
                    Product1(Product1.Length - 1)(0) = tmp(i)(m)
                    Product1(Product1.Length - 1)(1) = tmp(i)(m + 1)
                Next
            End If
        Next
    End Sub
    Private Function ProductOnly(ByVal N1 As Int32, ByVal N2 As Int32) As Boolean
        '判断是否为唯一积
        Dim i As Int32
        For i = 0 To Product1.GetUpperBound(0)
            If N1 = Product1(i)(1) AndAlso N2 = Product1(i)(0) Then Return True
            If N1 = Product1(i)(0) AndAlso N2 = Product1(i)(1) Then Return True
        Next
        Return False
    End Function
    Private Function SUMtoPRODUCT_N_2(ByVal SUM As Int32) As Int32
        '甲的和产生的积中最多有（n -2）个是唯一积
        Dim n As Int32 = CInt(SUM / 2 - 0.2)
        Dim i, m As Int32
        For i = 1 To n
            If ProductOnly(i, SUM - i) Then m += 1
        Next
        Return n - m
    End Function
    Private Function PROCUCTtoSUM(ByVal PRODUCT As Int32) As Boolean
        '乙的积产生的和中有且只有一个满足1、不是唯一和 2、和产生的积中最多有（n -2）个是唯一积
        '并且其余的和均满足 1、不是唯一和 2、有n－1个唯一积
        Dim tmp()(), i, m, n As Int32
        '1、分解积看能产生多少个和
        For i = 1 To CInt(Math.Sqrt(PRODUCT) - 0.4)
            If PRODUCT Mod i = 0 Then
                If tmp Is Nothing Then
                    ReDim tmp(0)
                    ReDim tmp(0)(2)
                Else
                    ReDim Preserve tmp(tmp.Length)
                    ReDim Preserve tmp(tmp.Length - 1)(2)
                End If
                tmp(tmp.Length - 1)(2) = PRODUCT / i
                tmp(tmp.Length - 1)(1) = i
                If Not SumOnly(tmp(tmp.Length - 1)(1), tmp(tmp.Length - 1)(2)) And SUMtoPRODUCT_N_2(i + PRODUCT / i) >= 2 Then
                    '和不为唯一和，且和产生的积中支多有n－2个是唯一积
                    tmp(tmp.Length - 1)(0) = 1
                End If
                If SumOnly(tmp(tmp.Length - 1)(1), tmp(tmp.Length - 1)(2)) Then
                    '唯一和
                    tmp(tmp.Length - 1)(0) = 3
                End If
                If Not SumOnly(tmp(tmp.Length - 1)(1), tmp(tmp.Length - 1)(2)) And SUMtoPRODUCT_N_2(i + PRODUCT / i) = 1 Then
                    '不是唯一和，但是有n－1个唯一积
                    tmp(tmp.Length - 1)(0) = 2
                End If
            End If
        Next
        Dim count As Int32 = 0
        For i = 0 To tmp.Length - 1
            If tmp(i)(0) = 0 Then Return False
            If tmp(i)(0) = 1 Then count += 1
        Next
        If count <> 1 Then Return False
        Return True
    End Function