## 树状数组

| \# | 题名 | 题解 | 通过率 | 难度 | 出现频率   |
|------|----------------------|-----|--------|----|--------|
|327|[区间和的个数](https://leetcode-cn.com/problems/count-of-range-sum)   |[13](https://leetcode-cn.com/problems/count-of-range-sum/solution)|31.8%|困难|32.98%|
|218|[天际线问题](https://leetcode-cn.com/problems/the-skyline-problem)   |[25](https://leetcode-cn.com/problems/the-skyline-problem/solution)|39.7%|困难|32.75%|
|308|[二维区域和检索 - 可变](https://leetcode-cn.com/problems/range-sum-query-2d-mutable)   |[12](https://leetcode-cn.com/problems/range-sum-query-2d-mutable/solution)|55.3%|困难|28.92%|
|493|[翻转对](https://leetcode-cn.com/problems/reverse-pairs)   |[15](https://leetcode-cn.com/problems/reverse-pairs/solution)|21.2%|困难|27.4%|
|307|[区域和检索 - 数组可修改](https://leetcode-cn.com/problems/range-sum-query-mutable)   |[25](https://leetcode-cn.com/problems/range-sum-query-mutable/solution)|52.5%|中等|19.86%|
|315|[计算右侧小于当前元素的个数](https://leetcode-cn.com/problems/count-of-smaller-numbers-after-self)   |[47](https://leetcode-cn.com/problems/count-of-smaller-numbers-after-self/solution)|36.7%|困难|18.47%|