#include <stdio.h>
int main()
{
    int i,x,flag;
    flag=1;
    printf("enter a positive integer :");
    scanf("%d",&x);
    for (i=2;i<x-1;i++)
    {
        if(x%i==0)
        {
            printf("%d is not a prime number.\n",x);
        }
   
        else
        {
            printf("%d is  a prime number.\n",x);
        }
    }
    return 0;
}

帮我看一下，这个编译之后，比如输入一个7后，它出现了4行7 is a prime number 是怎么回事啊