请问C语言中多余的空行是怎么回事呀？是编译器的问题吗？

Question

有一个C语言的编程练习，是输入正整数，然后显示所有小于该数的质数。
我写出来是这样的

#include <stdio.h>

int check_prime(long unsigned checking_num);

int main(void)
{
    long unsigned entered_num;
    long unsigned checking_num;
    int count = 0;

    printf("Enter an integer, this program will show you all the prime number less than the number you entered.\n");
    while (scanf("%lu", &entered_num) == 1)
    {
        printf("There are the following prime number less than the number you entered:\n");
        for (checking_num = 2,count = 0; checking_num < entered_num; checking_num++)
        {



            if (check_prime(checking_num) == 1)
            {

                printf("%lu\t", checking_num);
                count++;
            }
            if (count % 5 == 0)
                printf("\n");
        }
        printf("\n");

        if (count == 0)
            printf("There is no prime number less than the number you entered in.\n");
        printf("\nEnter another number to continue, Q to quit.\n");
    }

    return 0;

}

int check_prime(long unsigned checking_num)
{
    long unsigned div;
    int isprime;

    for (div = 2, isprime = 1; div*div <= checking_num; div++)
    {
        if ( checking_num % div == 0)
            isprime = 0;
    }

    return isprime;
}

其中有一个每输出5个质数就输出一个换行，但是不知道为什么总会多出来很多空行，截图如下
请大佬帮忙解决一下...

Answer 1

原因:程序有一个bug，以第一行举例，你运行到第五个素数时，下一个数为12同时count为5，此时if(素数)判断为false，往下执行if(count)语句为true，进入执行换行
解决方法:把判断count的if语句放在前面的if素数语句里面
望采纳