Many essential IV tasks are container methods, but this post is about STL algorithms.

— Tier 1: custom for() loop. More heavily quizzed than all other algorithms

— Tier 2:
find()
find_if() + filter
copy() + back_inserter
copy() + ostream_iterator
swap()
reverse()
sort() + comparitor. For random access iterators only i.e. vector/deque. Only these 2 containers. Yet sort() is important to IV because … hold your breath… because vector commands 50% “market share” among all IV containers.

— Tier 3:
container.erase + remove()
count()
for_each()

— Tier 9:
transform()? I guess interviewer can't assume all candidates use it regularly
all the rest