编程二十四点怎么编vb

时间:2025-01-28 02:04:16 网络游戏

```vb

Module VB24Point

Sub Main()

Dim numbers(3) As Integer

Dim operators(3) As String

Dim result As Double

Dim i As Integer

Dim j As Integer

Dim k As Integer

Dim l As Integer

' 输入四个数字

Console.WriteLine("请输入四个数字(用空格分隔):")

For i = 0 To 3

numbers(i) = Convert.ToInt32(Console.ReadLine())

Next

' 生成所有可能的数字排列

For j = 0 To 3

For k = 0 To 3

For l = 0 To 3

If j <> k And j <> l And k <> l Then

' 交换数字位置

numbers(j), numbers(k) = numbers(k), numbers(j)

Exit For

End If

Next

Next

Next

' 生成所有可能的运算符组合

For j = 0 To 3

For k = 0 To 3

For l = 0 To 3

If j <> k And j <> l And k <> l Then

operators(j) = "+"

operators(k) = "-"

operators(l) = "*"

Exit For

End If

Next

Next

Next

' 穷举所有可能的表达式

For j = 0 To 3

For k = 0 To 3

For l = 0 To 3

If j <> k And j <> l And k <> l Then

' 计算当前表达式的结果

result = CalculateExpression(numbers(0), operators(0), numbers(1), operators(1), numbers(2), operators(2), numbers(3), operators(3))

If result = 24 Then

Console.WriteLine($"找到解:{numbers(0)}{operators(0)}{numbers(1)}{operators(1)}{numbers(2)}{operators(2)}{numbers(3)}{operators(3)} = 24")

Exit For

End If

End If

Next

Next

Next

Console.WriteLine("没有找到解。")

Console.ReadLine()

End Sub

Function CalculateExpression(ByVal a As Integer, ByVal op1 As String, ByVal b As Integer, ByVal op2 As String, ByVal c As Integer, ByVal op3 As String, ByVal d As Integer, ByVal op4 As String) As Double

Dim result As Double

Select Case op1

Case "+"

result = a + b

Case "-"

result = a - b

Case "*"

result = a * b

Case "/"

If b <> 0 Then

result = a / b

Else

Return Double.NaN

End If

Case Else

Return Double.NaN

End Select

result = result + c

Select Case op3

Case "+"

result = result + d

Case "-"

result = result - d

Case "*"

result = result * d

Case "/"

If d <> 0 Then

result = result / d

Else

Return Double.NaN

End If

Case Else

Return Double.NaN

End Select

result = result + op4

Select Case op4

Case "+"

result = result + d

Case "-"

result = result - d

Case "*"

result = result * d

Case "/"

If d <> 0 Then

result = result / d

Else

Return Double.NaN

End If

Case Else

Return Double.NaN

End Select

Return result

End Function

End Module

```

这个程序首先输入四个数字,然后生成所有可能的数字排列和运算符组合。接着,它通过调用 `CalculateExpression` 函数来计算每个表达式的结果,并检查结果是否为24。如果找到解,程序将输出该表达式。

请注意,这个程序是一个简单的示例,实际应用中可能需要考虑更多的优化和错误处理。