The problem is that every card can be used just once and you have to divide them into two piles, so lets make the problem a bit easier and just use numbers 1-10.
For example take these two solutions:
Parent 1: 1 2 5 7 8 - 3 4 6 9 10 Parent 2: 1 4 5 6 9 - 2 3 7 8 10
In this case, we can't just split them and combine, you'll end up with duplicate numbers. So how do we create healthy children from this? One approach I usually see is to take one of the solutions as 'main' parent.
For example Parent 1, and we take half of the parent:
Child 1: 1 * 5 * 8 - * 4 * 9 * Child 2: * 2 * 7 * - 3 * 6 * 10
Next we take our second parent and use it to fill the missing blanks:
Parent 2: 1 4 5 6 9 - 2 3 7 8 10 Child 1: 1 * 5 * 8 - * 4 * 9 * First we filter out the ones used in child 1: 6 - 2 3 7 10 Next we try to fill the blanks as good as possible: 1 5 6 8 * - 2 3 4 7 9 Now assign the leftovers (they jump side). The resulting children will be: Child 1: 1 5 6 8 10 - 2 3 4 7 9 Child 2: 1 2 4 5 7 - 3 6 8 9 10
There are some problems with this idea, namely that for example the 10 in child 1 has jumped sides, and both parents had them in the second pile. This can be countered by first fixating numbers that are the same in both piles.
Just be creative, you'll find a method that works best for your situation.
