Re: [理工] [資結]-成大97-資工 程式設計
※ 引述《shinhwabo (.....)》之銘言:
Solving the recurrence T(n)=2T(└√n┘)+㏒n using big-O notation as
tight as possible
求板上的高手幫忙解答 thx
Assume T(1) = O(1)
T(n) = 2T(n^1/2) + logn
= 2{2T(n^1/4) + log(n^1/2)} + logn
= 4T(n^1/4) + 2*(1/2)logn + logn
= 4T(n^1/4) + 2logn
= (2^k)T(n^(1/2^k)) + klogn ----(a)
//拍謝, 剛剛導錯, 以下修正
T(2) = 2T(1) + log2 = O(1)
則令 n^(1/2^k) = 2 得 k = loglogn
T(n) = logn*T(2) + (loglogn)(logn)
= O(loglogn * logn)
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 58.114.130.207
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 114.32.189.59
推
02/06 13:35, , 1F
02/06 13:35, 1F
※ 編輯: IDontBite 來自: 114.32.189.59 (02/06 13:52)
推
02/06 23:24, , 2F
02/06 23:24, 2F
→
02/06 23:35, , 3F
02/06 23:35, 3F
推
03/04 23:15, , 4F
03/04 23:15, 4F
討論串 (同標題文章)
完整討論串 (本文為第 2 之 3 篇):