#include <stdio.h>
#include <math.h>

void main()
{
    int i,j,k,n=0;
    for(i=0;i<=100;i++)
    {        
        if(i=2)
        {
            n++;
            if(n%5==0) printf("\n");
            printf("%d\t",i);
        }        
        else
        {
            k=(int) sqrt(i*1.0);
            for(j=2;j<=k;j++)
            {
                if(i%j==0) break;
            }
            if(j>=k+1)
            {
                n++;
                if(n%5==0) printf("\n");
                printf("%d\t",i);
            }
        }
    }

}      要求求0-100的质数，一行输出5个

谢谢，确实是该==2，疏忽了