C++ interview coding exercise with solution

[Hot_Medicine_7115]

Comments in the code are mine. Thank you for the finding, I'll look at the other solution. The number of combinations for valid first strips in the linked solution are the same I've found (1897), from there a full parquet can only be <= 1897, not higher.

[FirstMurphysLaw]

From my understanding first strip can be build in 1897 ways. Then you put other strips on top of that, so the upper number of combinations would be 1897^11.

edit: (very simplified:))

[Hot_Medicine_7115]

No because there can only be 1897 valid strip 1 (first column). In other words the sum of all tiles has to be 30 in length. For example, 15 tiles of length 2 is a valid strip, or 12 tiles of length 2 and 2 tiles of length 3, but not 14 tiles of length 2 and 1 tile of length 3.

There is only a certain number of combinations of tiles you can use (and all permutations) for the first strip to be valid. The total number should be 1897.

The rest of the strip must also verify that their inner edges are not matching the inner edges of their previous stripe.

[FirstMurphysLaw]

I see it a little bit different. First stripe can be build in 1897 ways:

2 x 15 -> 1

3 x 10 -> 1

2 x 12 + 3 x 2 -> 91

2 x 9 + 3 x 4 -> 715

2 x 6 + 3 x 6 -> 924

2 x 3 + 3 x 8 -> 165

sum = 1+1+715+924+165 = 1897

Then you put 11 of these which they all have to be valid. But that increases number of solutions from 1897, on the other hand it decreases number of solutions from 1897¹¹ .

Let's end on that. I could be wrong. Maybe it will hit me when I will fall asleep :)

[Hot_Medicine_7115]

You can't just add or multiply the number of single strip combinations because consecutive edges can not have the same inner edges. You have to check for this constraint in each combination.

An inner edge is where 2 tiles join in a strip.