Hi there!
I've been struggling with validation that I needed to perform on some data and I hope this might help someone.
Problem: check if a large non sequential list contains some number with the expected outcome being true or false.
YouTube suggested me this video where they talk about what is Binary Search and I tried it and to my amusement it worked.
The previous query ran for 4 hours and by implementing this instead of List.Contains, the run time reduced to 1h25minutes!
As they say on the video, the list must be sorted in a ascending order.
let
f=
(_list as list, _x as any, _t as number, _b as number) as logical =>
if _t>_b then false else
let
_m = Number.Round((_t+_b)/2,0)
in
if _x<_list{_m} then @f(_list, _x, _t, _m-1) else
if _x>_list{_m} then @f(_list, _x, _m+1, _b) else
true
in
f
I also did a limited test with text and it seemed to work.
