Question

急求VB程序改错题高手，每个FOUND下一行有错误，请改正！十万火急！

'题目：已知C的公式表示如下:
' n!
' C=------------------
' (n-m)!*m!

'函数过程fac( )求k！函数,在Fomr_Click事件中完成运算，
'请修正程序中错误。

'------------------------------------------------
Option Explicit
Private Function fac(k As Integer) As Single
Dim x As Single, j As Integer
'**********FOUND**********
x = 0
For j = 1 To k
'**********FOUND**********
x = x ^ j
Next j
fac = x
End Function
Private Sub Form_Click()
Dim C As Single
Dim m As Integer, n As Integer
m = Val(InputBox("请输入一个整数(m)："))
n = Val(InputBox("请输入一个整数(n)："))
'**********FOUND**********
C = fac(n) / fac(n - m) * fac(m)
Print "C="; C
End Sub

Answer 1

1、x = 0 (不管怎么乘都是0,0乘任何数都为0) 应该为 x=1
2、 x = x ^ j (表示x的j次方) 应该为 x = x *j
3、C = fac(n) / fac(n - m) * fac(m) （乘除的优先级别一样 按照次序进行，即先除再乘）
应该为 C = fac(n) /( fac(n - m) * fac(m))

Answer 2

Option Explicit
Private Function fac(k As Integer) As Single
Dim x As Single, j As Integer
'**********FOUND**********
x = 1
For j = 1 To k
'**********FOUND**********
x = x * j
Next j
fac = x
End Function
Private Sub Form_Click()
Dim C As Single
Dim m As Integer, n As Integer
m = Val(InputBox("请输入一个整数(m)："))
n = Val(InputBox("请输入一个整数(n)："))
'**********FOUND**********
C = fac(n) / (fac(n - m) * fac(m))
Print "C="; C
End Sub