Combinations

Hi , I have to write a program that calculates the number of possible combinations k of n objects.
It has to be a recursive program.
It compiles and runs, but while debugging while I type in some numbers it returns 0 everytime

Thanks for any help

Code:

#include <stdio.h>
int possibleCombi(int n,int k);
int main (void)
{
   int n,k,combinations;
   printf("type in n , number of total objects");
   scanf("%d",&n);
   printf("type in k , numbers drawn");
   scanf("%d",&k);
   combinations = possibleCombi(n,k);
   printf("%d",combinations);
}

int possibleCombi(int n,int k)
{
	if ((k = 0) || (n = k)){
		return 1;
	}
	if(n > k > 0){
		return (possibleCombi(n - 1,k) + possibleCombi(n - 1,k - 1));
	}
	
}

I'm pretty sure this is not what you want:

Code:

  	if(n > k > 0){

This evaluates to ...

Code:

  if ((n > k) > 0) {

which means: if the boolean result of n > k (either "true" or "false") is > 0 do....

You probably want something like

Code:

  if ((n > k) && (k > 0)) {

Thanks , I made that change to my code, but it still returns a zero everytime

You're assigning k and n to 0 in the if statement try:

if ((k == 0) || (n == k)){

Thanks , it works now , except that the answer isn't right I think.
Shouldn't the answer for example with n = 8 and k = 3 be 512.
Instead it returns then 56

56 is correct

>Shouldn't the answer for example with n = 8 and k = 3 be 512
you must be a little confused.

that would be
8^3 = 512 (not XOR)
8*8*8 = 512