Math crossing out

Question

I am looking to play around with probability that involves a lot if big numbers. To save computing time, I was thinking about having the computer cross out terms like you do in regular math. For example:

(2*3*7*3) / (3*2*3*3)

Can be simplified to 7/3

If I were to create a Javascript function and pass it two arrays containing multiplication numbers to cross out, how would I go about doing this?

Just to be clear:

If I passed in [3, 4, 6, 4] and [4, 7, 3, 2], it would return two arrays: [4, 6] and [7, 2]

Answer 1

If you do not require cancellation beyond exact numbers, this should do:

var x = [3, 4, 6, 4];
var y = [4, 7, 3, 2];
for(var i in x)
{
  for(var j in y)
  {
    if(x[i]==y[j])
    {
      x.splice(i,1);
      y.splice(j,1);
    }
  }
}
console.log(x);
console.log(y);

But in case you are interested in further cancellation take this:

var x = [3, 4, 6, 4];
var y = [4, 7, 3, 2];
for(var i in x)
{
  for(var j in y)
  {
    if(x[i]%y[j] == 0)
    {
      if(x[i]/y[j] > 1)
      {
        x[i] = x[i]/y[j];
      }
      else{
        x.splice(i,1);
      }
      y.splice(j,1);
    }
  }
}

console.log(x);
console.log(y);