High-rise buildings

Hi everyone,

First of all, happy new year !

I’ve been searching a solution for this community puzzle and i’m about to change all my code because it’s not fast enough.

I solve 50% of the puzzle but on biggest map, my algorithm take too long. I did it the same way as i solved a sudoku previously, brute force + backtracking with some improvement (find the highest building on the map when it’s possible, even the “hidden” one, don’t wanna talk too much about it so people can search too) and in my map i save all numbers possible at that position, so i don’t try useless numbers.

I read that you can do it with some a* algorithm with some good heuristic?

If you have advice or things to read to help me, thank you in advance.