用VB语言编写程序：输入一个正整数，判断该数是否是素数。

Answer 1

Private Sub Command1_Click()
Dim N As Long, Flags As Boolean
N = Val(Text1.Text)
Flags = True
For i = 2 To Sqr(N)
If N Mod i = 0 Then
Flags = False
Exit For
End If
Next
MsgBox N & IIf(Flags, "", "不") & "是一个素数"

End Sub

Answer 2

#include<stdio.h>
int main()
{
int m[10],i,j=0,k;
long n;
scanf("%ld",&n);
k=n;
while(k>0){k/=10;j++;}
i=j;
while(i--){m[i]=n%10;n/=10;}
while(j--)printf("%d",m[j]);
}

=============

#include<stdio.h>
#include<math.h>
int main()
{
int i,n;
scanf("%d",&n);
for(i=2;i<=sqrt(n);i++)
if(n%i==0){printf("%d 不是素数！",n);return 0;} //
printf("%d 是素数！",n);
}