C语言：模拟实现strstr函数，若是子串，输出子串后面的字符串，否则输出null

 #define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<assert.h>
#include<stdlib.h>
char *my_strstr(char *arr1, char *arr2)
{
 assert(arr1);
 assert(arr2);
 char *s1 = arr1;
 char *p = arr2;
 char *s2 = p;
 while (*s1 != '\0')
 {
  while ((*s1 != '\0') && (*s2 != '\0') && (*s1 == *s2))
  {
   s1++;
   s2++;
  }
  if (*s2 == '\0')
  {
   return s1;
  }
 }
 return NULL;
}
int main()
{
 char *arr1 = "abcdeff";
 char *arr2 = "abc";
 char *ret = my_strstr(arr1, arr2);
 printf("%s", ret);
 system("pause");
 return 0;
}