I am getting an error in my code please see to it

I am getting an error in my code and I couldn’t understand it please look into it https://ide.codingblocks.com/s/437923

Hello @av8055 try making this change:
const t&key

it is still not working kindly make the changes in the online side so that I can understand clearly

it is still not working

its working fine now:
recheck this:

it is not working in my sublime and also in the. online cb ide it shows code not compiled successfully there is an error in the top right corner

i think it is your system error then because it is running fine here.
you can see:

ok ill see to it but can u tell why we use const t &key . it worked fine in Prateek bhaiya’s case in the Vedic without it

actually i was also getting error withou using const but after using that it was fine.
so it totally depends on machines only.