Merge branch 'master' into add-longest-common-subsequence

Author: piyushkumar0707

DIRECTORY.md

@@ -36,6 +36,12 @@
 
 ## Dynamic Programming
   * [Longest Common Subsequence](https://github.com/TheAlgorithms/R/blob/HEAD/dynamic_programming/longest_common_subsequence.r)
+## Data Structures
+  * [Binary Search Tree](https://github.com/TheAlgorithms/R/blob/HEAD/data_structures/binary_search_tree.r)
+## Graph Algorithms
+  * [Dijkstra Shortest Path](https://github.com/TheAlgorithms/R/blob/HEAD/graph_algorithms/dijkstra_shortest_path.r)
+  * [Breadth First Search](https://github.com/TheAlgorithms/R/blob/HEAD/graph_algorithms/breadth_first_search.r)
+  * [Depth First Search](https://github.com/TheAlgorithms/R/blob/HEAD/graph_algorithms/depth_first_search.r)
 
 ## Mathematics
   * [Amicable Numbers](https://github.com/TheAlgorithms/R/blob/HEAD/mathematics/amicable_numbers.r)