#include<stdio.h>
#include<math.h>
viod main()
{
    int m,i,k;
    scanf("%d,&m);
        k=sqrt(m);
    for(i=2;i<=k;i++)
        if(m%i==0)break;
        if(i>k)printf("%d is a prime number\n",m);
        else printf("%d is not a prime number\n",m);
}

大学学习中的问题