好久没来了，过来更新一下

#include <asssert.h>

//kMP算法

char* my_strstr(const char* p1, const char* p2)

{

assert(p1 != NULL);

assert(p2 != NULL);

char *s1 = (char *)p1;

char *s2 = (char *)p2;

char *cur = (char *)p1;

if (!*p2)

{

 return (char *)p1;

}

while (*cur)

{

 s1 = cur;

 s2 = (char *)p2;

 while(*s1 && *s2  && !(*s1 - *p2))

 {

  s1++;

  s2++;

 }

 if (!*s2)

 {

  return cur;//找到字符串

 }

 if (*s1 == '\0')

 {

  return NULL;

 }

 cur++;

}

return NULL;//找不到字符串

}

int main()

{

char *p1 = "abbbcdef";

char *p2 = "bbc";

char* ret = my_strstr(p1, p2);

if (ret == NULL)

{

 printf("字串不存在\n");

}

else

{

 printf("%s\n", ret);

}

return 0;

}