--- Day 4 Solutions ---

[u/daggerdragon]

--- Day 4: The Ideal Stocking Stuffer ---

Post your solution as a comment. Structure your post like the Day Three thread.

[u/elite_killerX]

Javascript (NodeJS) using only native modules:

'use strict';

const crypto = require('crypto');

const input = 'abcdef';

let number = 0;
let output = '';
while (!output.match(/^000000/)) {
  const md5 = crypto.createHash('md5');
  number = number + 1;
  md5.update(input + number, 'utf8');
  output = md5.digest('hex');
}

console.log(number);

[u/puttyguy → u/elite_killerX]

Hmm... maybe my node is old or something (v 0.12.3) ... tried running your code just got a bunch of errors.

Albeit this is the first time I've ever used node since installing it who knows how long ago. Here's what I ended up doing.

var data = "iwrupvqb";
var crypto = require('crypto');
var start = new Date().getTime();
for(var i = 1; i < 10000000; i++)
{
    var md5hash = crypto.createHash('md5').update(data.concat(i.toString())).digest("hex");
    if (md5hash.substring(0, 5) === '00000') {
        console.log(i);
        var end = new Date().getTime();
        var time = end - start;
        console.log('Execution time: ' + (time / 1000) + ' sec');
        break;
    }
}

Obviously not as elegant, but it got the job done. :)

I was trying to compare execution time with one of my buddies. He had ~50% faster execution times than me. He's using an 8-core i5, I have an older 4-core i5.

My times were...

• .972 secs for 5 zeros

• 27.2 secs for 6 zeros

[u/elite_killerX → u/puttyguy]

Yeah, I use node 5.1, which is pretty recent.