People in America are charmingly direct, and Bostonians even more-so . Perhaps it is because I am a foreigner but I have had more random conversations in the last 3 months than in all the years I lived in Auckland.
The following slice-of-life took place during my walk in The Blue Hills Reservation. I was climbing up a narrow, rocky incline when I stopped to let a group of older people scramble down. One of the group, a man of about 60, apologized for the delay and I told him I didn't mind. He immediately picked up on my accent.
It turns out that Prefix Tree is just another name for a Trie. If that is what he meant then I have implemented a prefix tree as an experiment at a previous job. It didn't work out, tries have a lot of overhead.
I wonder what would have happened if I had said yes.