Concepts2
⚙️AlgorithmIntermediate
Prefix Sum and Difference Array
Prefix sums precompute running totals so any range sum [l, r] can be answered in O(1) time as prefix[r] - prefix[l-1].
#prefix sum#difference array#imos method+12
⚙️AlgorithmIntermediate
Coordinate Compression
Coordinate compression replaces large, sparse, or arbitrary values with small consecutive integers while preserving relative order.
#coordinate compression#discretization#lower_bound+12