Create README.md

Author: rahulkumaran

Competitive Coding/Math/Catalan_Numbers/README.md

@@ -0,0 +1,21 @@
+The 2 different programs in this folder contain the same implementation!
+The programs basically are a python implementation of the Catalan Numbers.
+They're similar to Fibonacci (very slightly)
+
+The 2 different implementations vary only in terms of time taken!<br>
+Basically we can implement in 3 different ways!<br>
+
+(1) Recursively <br>
+(2) Dynamic Programming <br>
+(3) Binomial Coefficient <br><br>
+
+Each of the above 3 implementations have a descending order of time complexities from (1) to (3) <br><br>
+
+For (1) the time complexity is exponential<br>
+For (2) the time complexity is O(n^2)<br>
+For (3) the time complexity is O(n)<br><br>
+
+The Binomial implementation has the best time complexity while the Recursive implementation has the worst time complexity<br>
+In this folder we have the Binomial and Recursive implementations of Catalan Numbers.<br><br>
+
+Sources : https://www.geeksforgeeks.org/program-nth-catalan-number/ (You can have a look at this to know more about Catalan number implementations and its theory.)