Comment by charlieyu1

I actually think precomputing the numbers with digit sum 30 is the best approach. I'd give a very rough estimate of 500-3000 candidates because 30 is rather high, and we only need to loop for the first 4 digits because the fifth can be calculated. After that, it is O(1) set/dict lookups for each of the 1000000 numbers.

Everything can also be wrapped in list comprehensions for top performance.