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src/data-structures/tree/binary-search-tree/README.md

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+# Binary Search Tree
+
+In computer science, binary search trees (BST), sometimes called 
+ordered or sorted binary trees, are a particular type of container: 
+data structures that store "items" (such as numbers, names etc.) 
+in memory. They allow fast lookup, addition and removal of 
+items, and can be used to implement either dynamic sets of 
+items, or lookup tables that allow finding an item by its key 
+(e.g., finding the phone number of a person by name).
+
+Binary search trees keep their keys in sorted order, so that lookup 
+and other operations can use the principle of binary search: 
+when looking for a key in a tree (or a place to insert a new key), 
+they traverse the tree from root to leaf, making comparisons to 
+keys stored in the nodes of the tree and deciding, on the basis 
+of the comparison, to continue searching in the left or right 
+subtrees. On average, this means that each comparison allows 
+the operations to skip about half of the tree, so that each 
+lookup, insertion or deletion takes time proportional to the 
+logarithm of the number of items stored in the tree. This is 
+much better than the linear time required to find items by key 
+in an (unsorted) array, but slower than the corresponding 
+operations on hash tables.
+
+A binary search tree of size 9 and depth 3, with 8 at the root.
+The leaves are not drawn.
+
+![Binary Search Tree](https://upload.wikimedia.org/wikipedia/commons/d/da/Binary_search_tree.svg)
+
+## References
+
+[Wikipedia](https://en.wikipedia.org/wiki/Binary_search_tree)