C语言的改错问题（小的程序问题，请各位看下！）

Question

该程序完成按每行5个的格式输出所有3位数中的质数，函数judge用来判断一个整数是否为质数。
程序存在一些错误，要指出具体出错行的行号并说明出错原因（每行代码后我给出的注释内容为行号），且在不改动程序的框架、变量定义的基础上给出正确的程序代码，或者说明将出错行做怎样的修改。
跑了好几遍代码并且尝试修改之后还是不行，显示错误，实在是看不出来了，还请在座的各位帮忙看看，谢谢！
#include <stdio.h> //1
#include <math.h> //2
int judge(int n) //3
{ //4
int i, k; //5
k = (int)sqrt(n); //6
for (i = 1; i <= k; i++) //7
if (!n % i ) //8
return 0; //9
else return 1; //10
} //11
int main() //12
{ //13
int count ,i; //14
for (i=101;i<1000;i=i+2) //15
if (judge(i)) //16
{ //17
printf("%5d", i); //18
count++; //19
} //20
if (count % 5 == 0) //21
printf("\n"); //22
return 0; //23
} //24
边跑边改，一直不对，麻烦各位帮忙看看啦！

Answer 1

#include <stdio.h> //1
#include <math.h> //2
int judge(int n) //3
{ //4
int i, k; //5
k = (int)sqrt(n); //6
for (i = 2; i <= k; i++) //7
if (n % i==0 ) //8
return 0; //9
return 1; //10
} //11
int main() //12
{ //13
int count=0 ,i; //14
for (i=101;i<1000;i=i+2) //15
if (judge(i)) //16
{ //17
printf("%5d", i); //18
count++; //19
if (count % 5 == 0) //21
printf("\n"); //22
} //20
return 0; //23
} //24