Print a line where missing!!

Hi,
I have a file whihc looks like

file_1 100 200
file_2 200 300
file_4 400 500

as the file_3 is missing so I want to replace it by
file_3 0 0

the final output would look like

file_1 100 200
file_2 200 300
file_3 0 0
file_4 400 500

Any help is highly appreciated.

Regards,

Seems like a duplicate thread. Posted a solution here