/*
node depanancies:
npm install bignum
*/

var bignum = require('bignum');
var diff1 = bignum('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF', 16);

// This is what miner submits
var powHash;

// Grab this from https://xmrchain.net
powHash = 'a70043cad329b7d1af2d6d1b93a3d8e86159d6ab17f73875a8f9d80000000000';

// var hash = new Buffer(powHash, 'hex');
var hash = Buffer.from(powHash, 'hex');

var hashArray = hash.toJSON().data.reverse();
var hashNum = bignum.fromBuffer(Buffer.from(hashArray));

var hashDiff = diff1.div(hashNum);

console.log(hashDiff.toString());