Hi all,

Some time ago I’ve been thinking about a programming challenge that’s not simply another HackerRank style algorithm task and came up with something that I myself had a lot of fun solving. It goes like this:

We have a well known function (as in I didn’t come up with it):

```
function xoshiro128ss(a, b, c, d) {
return function() {
var t = b << 9, r = b * 5; r = (r << 7 | r >>> 25) * 9;
c ^= a;
d ^= b;
b ^= c;
a ^= d;
c ^= t;
d = d << 11 | d >>> 21;
return (r >>> 0) / 4294967296;
}
}
```

We initialize it with 4 random parameters **a,b,c,d** (that I selected) :

```
let rnd = xoshiro128ss(a, b, c, d);
```

and we do:

```
let rand1 = rnd();
let rand2 = rnd();
let rand3 = rnd();
let rand4 = rnd();
```

Knowing that:

```
rand1 == 0.38203435111790895
rand2 == 0.5012949781958014
rand3 == 0.5278898433316499
rand4 == 0.5114834443666041
```

**What are the values of a,b,c and d?**

I was wandering if it’s possible to figure it out and couldn’t stop trying until I did. It was an interesting journey and I learned some new things along the way Maybe someone else here will also have fun with it. As for prizes, I don’t know… whoever posts the right answer first gets an upvote and eternal fame.

I think that’s the issue, in the second possible solution one of the parameters is negative :)

This looks great, I didn’t even know it’s possible to solve it this way. I’m glad someone dedicated some time to it. Let’s see if anyone will try solving it in other way.