* 时间复杂度：O(len1 + len2)，空间复杂度：O(len2)（栈+Map的空间）
4．报送内容：公司名、公司注册地、船名、IMO号、MMSI号、船型、船旗国、始发港、 目的港、计划驶入时间、计划驶出时间、船员人数（分国别）等。
。业内人士推荐服务器推荐作为进阶阅读
As a child, Kaley set up multiple accounts on both Instagram and YouTube so she could like and comment on her posts. She said she would also “buy” likes through a platform where she could like other people’s photos and get a slew of likes in return. “It made me look popular,” she said.
The value of an NFT comes from its ability to be traded freely and securely on the blockchain, which is not possible with other current digital ownership solutionsThe NFT points to its location on the blockchain, but doesn’t necessarily contain the digital property. For example, if you replace one bitcoin with another, you will still have the same thing. If you buy a non-fungible item, such as a movie ticket, it is impossible to replace it with any other movie ticket because each ticket is unique to a specific time and place.