# Bit

- [307.Range-Sum-Query---Mutable](/leetcode/bit/307.range-sum-query-mutable.md)
- [308.Range-Sum-Query-2D---Mutable](/leetcode/bit/308.range-sum-query-2d-mutable.md)
- [315.Count-of-Smaller-Numbers-After-Self](/leetcode/bit/315.count-of-smaller-numbers-after-self.md)
- [493.Reverse-Pairs](/leetcode/bit/493.reverse-pairs.md)