#include <stdio.h>
#include <math.h>
main()
{
    int j = 0, n, k, i,flag;
    printf("\n");
    for (n = 3; n < 100; n = n + 2 )
    {
        k = sqrt((double)n);
        i = 2;
        flag = 0;
        while((i < = k)&&(flag ==0))

        {
            if(n % i == 0 ) falg= 1;
            i = i + 1;
        }
        if(flag == 0)
        {
            j = j +1;
            printf("%d", n);
            if (j % 10 = 0)
            printf("\n");
        }
    }
    printf("\n");
}

都是小错误...

#include <stdio.h>
#include <math.h>
main()
{
    int j = 0, n, k, i,flag;
    printf("\n");
    for (n = 3; n < 100; n = n + 2 )
    {
        k = sqrt((double)n);
        i = 2;
        flag = 0;
        while((i <= k)&&(flag == 0))

        {
            if(n % i == 0 ) flag= 1;          //楼主这这这......
            i = i + 1;
        }
        if(flag == 0)
        {
            j = j +1;
            printf("%d ", n);
            if (j % 10 == 0)                //这一步..
            printf("\n");
        }
    }
    printf("\n");
}

楼主是想把1-100的素数打印出来是吧.

对啊
就是把1到100的素数打出来
每行十个

楼主的代码基本没有错误:
1:  falg= 1;  改为 flag = 1;
2: if (j % 10 = 0)   改为 if(j % 10 == 0)

#include <stdio.h>
#include <math.h>
main()
{
    int j = 0, n, k, i,flag;
    printf("\n");
    for (n = 3; n < 100; n = n + 2 )
    {
        k = sqrt((double)n);
        i = 2;
        flag = 0;
        while((i <=k)&&(flag ==0))

        {
            if(n % i == 0 ) flag=1;//flag写错
            i = i + 1;
        }
        if(flag == 0)
        {
            j = j +1;
            printf("%3d", n);
            if (j % 10==0) //=改为==
            printf("\n");
        }
    }
    printf("\n");
    getch();
}

新人路过啦