I have a doubt in syntax part

#1

At 22:41, what does the mean of " (mask|(1<<city)) " ?

#2

hello @chandreshmaurya

we are setting the bit true with this syntax in mask.
1<<city will give number which will have only one set bit at position = city.
and then taking its or with mask will set that it(mask) bit at position=city

#3

I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.

On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.