[Swift]LeetCode493. 翻转对 | Reverse Pairs
Givenanarray nums,wecall (i,j) an importantreversepair if i<j and nums[i]>2*nums[j].Youneedtoreturnthenumberofimportantreversepairsinthegivenarray.Example1:Input:[1,3,2,3,1]Output:2 Example2:Input:[2,4,3,5,1]Output:3