c语言模拟实现strstr（在一个字符串中寻找另一个字符串）

#include

char* my_strstr(const* str1, const* str2)
{
	const char* s1 = NULL;
	const char* s2 = NULL;
	const char* cp = str1;

	if (*str2 ==  '')
	{
		return (char*)str1;
	}
	while (*cp)
	{
		s1 = cp;
		s2 = str2;
		while (*s1 && *s2 && (*s1 == *s2))
		{
			s1++;
			s2++;
		}
		if (*s2 == '')
		{
			return (char*)cp;
		}
		cp++;
	}
	return NULL;
}

int main()
{
	char arr1[] = "abcd";
	char arr2[] = "bc";
	char* ret = my_strstr(arr1, arr2);
	if (ret == NULL)
	{
		printf("没找到");

	}
	else
	{
		printf("找到了：%sn", ret);
	}
}

运行结果: