这个程序哪里错了啊怎么没有结果 啊?

#define M 1000
#include <stdio.h>
void main()
{
int k1,k2,k3,k4,k5,k6,k7,k8,k9,k10;
int i,a,n,s;
for(a=2;a<=M;a++)
{n=0;
s=a;
for(i=1;i<a;i++)
if(a%i==0)
{n++;
s=s-i;
switch(n)
case1:
k1=i;break;
case2:
k2=i;break;
case3:
k3=i;break;
case4:
k4=i;break;
case5:
k5=i;break;
case6:
k5=i;break;
case7:
k6=i;break;
case8:
k8=8;break;
case9:
k9=i;break;
case10:
k10=i;break;
}
}
if(s==0)
{
printf("%d,its factors are",a);
if(n>1) printf("%d,%d",k1,k2);
if(n>2) printf("%d",k3);
if(n>3) printf("%d",k4);
if(n>4) printf("%d",k5);
if(n>5) printf("%d",k6);
if(n>6) printf("%d",k7);

/* 好好看看就知道了*/

#define M 1000
#include <stdio.h>
void main()
{
int k1,k2,k3,k4,k5,k6,k7,k8,k9,k10;
int i,a,n,s;
for(a=2;a<=M;a++)
{n=0;
s=a;
for(i=1;i<a;i++)
if(a%i!=0)
{n++;
s=s-i;
switch(n)
{
case 1:
k1=i;break;
case 2:
k2=i;break;
case 3:
k3=i;break;
case 4:
k4=i;break;
case 5:
k5=i;break;
case 6:
k5=i;break;
case 7:
k6=i;break;
case 8:
k8=8;break;
case 9:
k9=i;break;
case 10:
k10=i;break;
}
} }
if(s)
{
printf("%d,its factors are",a);
if(n>1) printf("%d,%d\n",k1,k2);
if(n>2) printf("%d\n",k3);
if(n>3) printf("%d\n",k4);