3NPLUS1.c

#include <stdio.h>

unsigned long findMaxCycleLength(unsigned long min, unsigned long max);
unsigned long findCycleLength(unsigned long n);
     
int main(int argc, char** argv)
{
	unsigned long min, max, num = 0;

	while(scanf("%li %li", &min, &max) != EOF)
	{
		printf("%li %li ", min, max);
		if(min > max)
		{	
			min^=max;
			max^=min;
			min^=max;
		}
		num = findMaxCycleLength(min, max);
		printf("%li\n", num);
	}
}

unsigned long findMaxCycleLength(unsigned long min, unsigned long max)
{
	unsigned long temp, i;
	unsigned long n = findCycleLength(max);

	for(i = min; i < max; i++)
	{
		temp = findCycleLength(i);
		if(temp > n)
		{	
			n = temp;
		}
	}

	return n;
}

unsigned long findCycleLength(unsigned long n)
{
	if(n == 0) return 0;
	unsigned long count = 1;
	while(n != 1)
	{
		if(n%2 == 1)
		{
			n = 3*n+1;
		}
		else
		{
			n = n/2;
		}
		count++;
	}
	return count;
}