From a41326df5d1f4c7ac346d1d429a2d17201bcdf57 Mon Sep 17 00:00:00 2001
From: Ayush Agrawal <56473603+AyushAgrawal25@users.noreply.github.com>
Date: Sat, 2 Oct 2021 16:03:43 +0530
Subject: [PATCH] Catalan Numbers

This is a program to find nth Catalan number.
---
 Catalan_Number.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Catalan_Number.cpp

diff --git a/Catalan_Number.cpp b/Catalan_Number.cpp
new file mode 100644
index 00000000..cfd6ae5a
--- /dev/null
+++ b/Catalan_Number.cpp
@@ -0,0 +1,17 @@
+#include <stdio.h>
+// using recursive approach to find the catalan number
+unsigned long int catalan(unsigned int n) {
+   // Base case
+   if (n <= 1) return 1;
+   // catalan(n) is sum of catalan(i)*catalan(n-i-1)
+   unsigned long int res = 0;
+   for (int i=0; i<n; i++)
+      res += catalan(i)*catalan(n-i-1);
+   return res;
+}
+//Main function
+int main() {
+   int n = 6;
+   printf("catalan is :%ld\n", catalan(n));
+   return 0;
+}