C语言求素数的两种方法

1,判断n是否能被1~n-1整除

#include<stdio.h>
int main()
{
    int i, n;
    scanf("%d", &n);
    for (i = 2; i < n ; i++)
    {
        if (n%i == 0)
            break;
    }
        if (i < n) printf("This is not a prime.");
        else printf("This is a prime.");
        return 0;
}#include<stdio.h>
int mai