This is a 7-segment:
_ |_| |_|
It's a 3-by-3 char matrix.It has made by 3 characters: '_' , '|' and ' ' (space). Using these 3 characters make the input number on the 7-segment. (Input is 0-9).
Example:
N=0 ans= _ | | |_|
N= 9 ans= _ |_| _|
quite a job to find those binary code accordingly.