1) what's the performance benefit of using hash_maps over normal maps?
2) can i set multiple keys in either?
3) if i have a struct (with element: int x, y as an entry in the maps and I want to use this as a key, the sort order will be according to what? OR do I have to use let's say x as the other pair and set that as the key?
4) Multiple entries (same keys) in a map are overwritten. is it possible to count how many times this overwrite occurs and for which keys, without using other variables (except for storing answers, not for comparisions)?