Catalan Numbers

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;
+}