Results 1 to 2 of 2
 08062012, 08:08 AM #1Member
 Join Date
 Aug 2012
 Posts
 1
 Rep Power
 0
basic recursion problem  code needs to be modified
I need help fixing this! I just keep getting a million errors urgh > i need to figure out how to catch the exception (that n < r) properly and continue programming because i need to hard code two more values still (also suggestions on how to do that would be great) > the prompt is within the code
Java Code:/* The formula for computing the number of ways of choosing r different things from a set of n things is the following: C(n, r) = n! / (r! * (nr)!) Write a recursive program (name the class that contains the main method Activity2) that executes C(n, r) three times and prints the results. Your execution should use the (n, r) pairs as follows: (2, 4), (5, 3), and (24, 12). Hardcode these values and calls to the recursive method into your program. (Do not prompt the user to enter them.) Note that you will need to devise and program a recursive method that calculates the factorial of a value. In the event any of the pairs perform a calculation that throws any exception, catch the exception, print a suitable informative message and continue processing. */ import java.math.BigInteger; public class Activity2 { public static void main(String[] args) { try { int n=2; int r=4; System.out.print("C("+n+","+r+"): "); int fn=factorial(n); int fr=factorial(r); int fnr=factorial(nr); int ncr=fn/(fr*fnr); System.out.println(ncr); } catch (Exception e) {} } static int factorial(int n){ if (n==0) return 1; else return(n*factorial(n1)); } }

Re: basic recursion problem  code needs to be modified
your first problem... to solve the negative factorial errors:
Java Code:static int factorial(int n){ if (n<=0){ return 1; } else{ return(n*factorial(n1)); } }
to hard code several input numbers, instead of int variables use int[] arrays:
Java Code:int[] n = {2,5,24}; int[] r = {4,3,12};
Similar Threads

Recursion: Sierpinski Triangle Code Help
By Renee in forum New To JavaReplies: 2Last Post: 04242012, 05:16 PM 
Basic Java Calculator Code Problem
By SerbianSergeant in forum New To JavaReplies: 7Last Post: 07222011, 01:50 PM 
Is there a way to clean up this recursion code?
By SMHouston in forum New To JavaReplies: 2Last Post: 09302009, 02:30 AM 
very basic code
By BlueJ2008 in forum New To JavaReplies: 1Last Post: 10142008, 01:40 PM 
help with basic java code
By elizabeth in forum New To JavaReplies: 1Last Post: 08072007, 06:47 PM
Bookmarks