How to reduce a random hash to a boolean value

Question

In c or a c-like language assuming I have a random_hash what is the cheapest way to reduce it to a boolean value i.e. 0 or 1?

An example random_hash to normalise answers: 0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa

Restrictions: no method/stdlib calls.

Why c-like, I'm actually trying to do it in a language called Solidity, which is modeled after c/javascript, which has a very limited runtime/stdlib.

Answer 1

Take the largest or smallest bit from the hash and use this as the boolean. Actually, taking any bit should be fine, assuming a good hash function. Assuming the hash is an array of unsigned char, you can use the bitwise AND operator &

(hash[0] & 1) > 0