update readme.md

fuli · fuli · commit 81474a350f1a · 2013-10-18T16:05:46.000+08:00
diff --git a/README.md b/README.md
@@ -48,6 +48,7 @@
     Interval tree
     Prefix Tree(Trie)
     *Suffix Tree(未实现)*
+	B-Tree
 
     Hash by multiplication
     Hash table
