Prefix Tree implemented with C #-trie

After reading the masterpiece of Jeffery Zhao, I had the impulse to write a Prefix Tree, so it took a little time to implement it.

[Edit] found many vulnerabilities in this implementation and hidden them ...... Really want to see, click here to expand

Code:

 Using  System  .  Collections  .  Generic;  Namespace  Datastructure  .  Trees {  Public sealed class  Trie  <  Tkeyfragment, tvalue >  {  Private  Trienode  <  Tkeyfragment, tvalue  >  Root;  Public  Trie () {Root  =  New  Trienode  <  Tkeyfragment, tvalue  > ();}  Public  Trie (  Trienode  <  Tkeyfragment, tvalue  >  Root ){  This  .  Root  =  Root ;}  Public bool  Store (  Ienumerable <  Tkeyfragment  >  Key, tvalue value ){  Return  Root  .  Expand (Key  .  Getenumerator (), value );}  Public  Ienumerable  <  Tvalue  >  Lookfor ( Ienumerable  <  Tkeyfragment  >  Key ){  Return  Root  .  Lookfor (Key  .  Getenumerator ());}}  Public class  Trienode  <  Tkeyfragment, tvalue  > {  Protected  Dictionary  <  Tkeyfragment,  Trienode  <  Tkeyfragment, tvalue  >  Table  =  New  Dictionary  <  Tkeyfragment,  Trienode  < Tkeyfragment, tvalue  >  ();  Protected  List  <  Tvalue  >  Valuecollection  =  New  List  <  Tvalue  >  ();  Protected internal virtual bool Expand (  Ienumerator  <  Tkeyfragment  >  Keyenumerator, tvalue value ){  If  (Keyenumerator  .  Movenext ()){  VaR  Nextfragment  =  Keyenumerator  .  Current; If  (  !  Table  .  Containskey (nextfragment) {table  .  Add (nextfragment,  New  Trienode  <  Tkeyfragment, tvalue  >  ());}  Return  Table [nextfragment] .  Expand (keyenumerator, value );}  Else  {  If  (  !  This  .  Valuecollection  .  Contains (value )){  This  .  Valuecollection  . Add (value );}  Return true  ;}}  Protected internal virtual  Ienumerable  <  Tvalue  >  Lookfor (  Ienumerator  <  Tkeyfragment  >  Keyenumerator ){  If (Keyenumerator  .  Movenext ()){  VaR  Nextfragment  =  Keyenumerator  .  Current;  If  (  !  Table  .  Containskey (nextfragment )){  Return new List  <  Tvalue  >  ();}  Return  Table [nextfragment]  .  Lookfor (keyenumerator );}  Else  {  Return  Valuecollection ;}}}} 

The key type must be ienumerable <tkeyfragment>. The usage is simple:

 Class Program  {  Static void  Main (  String  [] ARGs ){  VaR  Mytrie  =  New  Trie  <  Char  ,  String  >  (); Mytrie  . Store (  "I love you"  ,  "Guys"  ); Mytrie  .  Store (  "I love you"  ,  "Cnblogs"  ); Mytrie  .  Store (  "I hate you"  ,  "Bad guy"  ); Mytrie .  Store (  "I hate you"  ,  "WTF"  ); Mytrie  .  Lookfor (  "I love you"  )  .  Tolist ()  .  Foreach (Str  =>  Console  . Writeline (STR); mytrie  .  Lookfor (  "I hate you"  )  .  Tolist ()  .  Foreach (Str  =>  Console  .  Writeline (STR ));}} 

I haven't thought about how to merge the intermediate nodes with no corresponding value. Let's go back and think about it.