谁看看哪里错了

#include<stdio.h>
#include<string.h>
main(void)
{
char a[10];
char *k,*p;
char c;
printf(" qing shu ru zi fu chuan\n");
gets(a);
printf("qing shu ru yao cha xun de zi fu\n");
scanf("%c",&c);
p=a;
k=strchr(p,c);
p=k;
while(k!=NULL)
{k=strchr(p,c);
printf("gai zi fu shi di %d ge zi fu\n\n",k-a+1);
p=k;
}
getch();
}

#include<stdio.h>
#include<string.h>
main(void)
{
char a[10];
char *k,*p;
char c;
printf(" qing shu ru zi fu chuan\n");
gets(a);
printf("qing shu ru yao cha xun de zi fu\n");
scanf("%c",&c);
p=a;
k=strchr(p,c);
p=k; //这句没用
while(k!=NULL)
{k=strchr(p,c); //这句话在p=k;后头
printf("gai zi fu shi di %d ge zi fu\n\n",k-a+1);
p=k;
}
getch();
}

正确的是：
#include<stdio.h>
#include<string.h>
main(void)
{
char a[10];
char *k,*p;
char c;
printf(" qing shu ru zi fu chuan\n");
gets(a);
printf("qing shu ru yao cha xun de zi fu\n");
scanf("%c",&c);
p=a;
k=strchr(p,c);
while(k!=NULL)
{
printf("gai zi fu shi di %d ge zi fu\n\n",k-a+1);
p=k;