Codeforces 597D Subsequences (二维树状数组入门+DP优化) 高清重制版
Forthegivensequencewithndifferentelementsfindthenumberofincreasingsubsequenceswithk + 1elements.Itisguaranteedthattheanswerisnotgreaterthan8·1018.InputFirstlinecontaintwointegervaluesnandk(1 ≤ n ≤ 105