Updated link file

Author: ankesh007

README.md

@@ -19,7 +19,7 @@ I would like to give due **credits** to respective slide/notes creators:
 Sorry if I missed any credits. 
 
 I will try adding more stuffs and keep this updated.
-Also I have added a 'link' file to add good links. Feel free to share and contribute.
+Also I have added a `link` file to link good **tutorials**. Feel free to share and contribute.
 
 I am also linking codebook we used in ICPC. There are many available online. [Click](https://github.com/ankesh007/Tested-Codes-for-Codebook)
 

links

@@ -1,6 +1,19 @@
+DP:
+===================
 https://www.topcoder.com/community/competitive-programming/tutorials/dynamic-programming-from-novice-to-advanced/
 
 Topic Wise:
-=============
+===================
+https://codeforces.com/blog/entry/23204
 
-https://codeforces.com/blog/entry/23204
+DS gym:
+===================
+https://codeforces.com/blog/entry/15729
+
+Graph gym:
+===================
+https://codeforces.com/blog/entry/16221
+
+Best of Tutorials:
+===================
+https://codeforces.com/blog/entry/57282