LeetCode 315: Count of Smaller Numbers After Self
A clear explanation of Count of Smaller Numbers After Self using coordinate compression and a Fenwick Tree.
Tag
Fenwick-Tree
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LeetCode 308: Range Sum Query 2D - Mutable
A clear explanation of Range Sum Query 2D - Mutable using a 2D Fenwick Tree for efficient updates and rectangle sum queries.
LeetCode 307: Range Sum Query - Mutable
A clear explanation of Range Sum Query - Mutable using a Fenwick Tree for efficient updates and range sums.
2.3 Fenwick Tree Variants
Fenwick tree construction, point and range updates, multidimensional extensions, order statistics, inversion counting, and persistent variants.