Ackermann Function

A Recursive Function that can only be implemented recursively. There is no iterative variant.

Function

With $m,n\ge 0$:

#include <stdio.h>
 
int ack(int m, int n){
	int asn;
	if (m == 0) ans = n+1;
	else if (n == 0) ans = ack(m-1, 1);
	else ans = ack(m-1, ack(m,n-1));
	return ans;
}