Collatz conjecture solver

(x%2==0) ? x/=2 : x=x*3+1;

You probably want the GMP version for arbitrarily big numbers. Get it from the GMP branch.

Program to solver the Collatz conjecture.

Algorithm:

• Start with number.
• If number is even, divide by two.
• If number is odd, multiply by three and add one.
• Repeat.

To figure out if it will repeat, save all the previous numbers, and check if the current number is one of those. If it is, that means it will repeat, and you have disproved the Collatz conjecture. So far, though, nobody has disproven it up to 2^68.