#include<stdio.h>
int main(void)
{
    unsigned long num;
    unsigned long div;
    int isPrime;

    printf("Please enter an integer for analysis;");
    printf("Enter q to quit.\n");
    while(scanf_s("%lu",&num)==1)
    {
        for(div=2,isPrime=1;(div*div)<=num;div++)
        {
            if(num%div==0)
            {
                if((div*div)!=num)
                    printf("%lu is divisible by %lu and %lu.\n",num,div,num/div);
                else
                    printf("%lu is divisible by %lu.\n",num,div);
                isPrime=0;
            }
        }
        if(isPrime)//这个语句是什么意思，有什么作用？
            printf("%lu is prime.\n",num);
        printf("Please enter an integer for analysis;");
    printf("Enter q to quit.\n");
    }
    printf("Bye bye!\n");
    getchar();
    return 0;
}
        
        

谢谢！