Standard Fenwick trees can only do prefix sums, which only get you general range queries on things with a subtraction operator, not operations like maximum. Th

Standard Fenwick trees can only do prefix sums, which only get you general range queries on things with a subtraction operator, not operations like maximum. The reddit comment I link contains an implementation that allegedly does arbitrary range queries, but it's nigh-incomprehensible so I can't tell how or why it uses 3 arrays.