- Reverse Pairs 难度 困难
https://leetcode-cn.com/problems/reverse-pairs/
Given an integer array nums, return the number of reverse pairs in the array.
A reverse pair is a pair (i, j) where 0 <= i < j < nums.length and nums[i] > 2 * nums[j].
Example 1:
Input: nums = [1,3,2,3,1]
Output: 2
Example 2:
Input: nums = [2,4,3,5,1]
Output: 3
Constraints:
1 <= nums.length <= 5 * 104
-231 <= nums[i] <= 231 - 1
相关标签
- Binary Indexed Tree
- Segment Tree
- Array
- Binary Search
- Divide and Conquer
- Ordered Set
- Merge Sort
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