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I have partially implemented a Patricia Trie, it's still not complete since it lacks a delete/remove function which is used to remove nodes from the Trie, I have found this article describing the structure, which comes with an implementation in C++, there's a remove/delete function, but I can't figure out what's the idea behind the implementation.

How do I remove a node from the Trie and leave the Trie in a proper state?

Brian Tompsett - 汤莱恩
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neevek
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  • Sorry for not having noticed your comment, I just started to use SO. I was trying to implement the structure in Java and C++, well, it can be any language, I only need to know the idea behind the implementation, not the implementation itself. Thanks for your reply. – neevek May 22 '11 at 11:37

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I've implemented a PATRICIA in C recently. In order to remove a node, find the down-trie node which points backward up the trie to the victim (this may be the victim node itself.)

Once found, if the victim node is NOT the backward-referer, switch the victim with its referer. This puts the victim close to being a "leaf" node, and its backward reference will be to itself. The removal is very simple, then.

Corey Brenner
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