Collatz conjecture solver

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

Program to solve the Collatz conjecture.

To build:

• With GMP: Run make -j1 (any more than -j1 doesn't really do anything, there's four things to do and they can't be put out of order).
• Without GMP: Run make gmpless -j1 (see above parenthetical statement).

Algorithm:

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