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看板Grad-ProbAsk作者 (Drinking)時間14年前 (2011/08/07 21:25), 編輯推噓2(204)
留言6則, 3人參與, 最新討論串2/4 (看更多)
98台大資工- Tru or False (d) The Hasse diagram for a total ordering is a chain (e) It is possible that there are multiple topological orders for a partially ordered set 想問這兩個選項.. ----------------------------------------------------------------- 98中山資工 Let R be the relation on A={1,2,3,4,5,6,7},where the directed graph associated with R consists of the two components,each a directed cycle ,shown below.Find all integers n's such that 1<n<30 and R^n = R 1 → 2 5 ↑ ↓ ↗ ↘ 4 ← 3   7 ← 6 這題解答部分是寫 R^(12k) 不太懂這個地方.. ------------------------------------------------------------------ 97清大資工 Let S be the set of all strings of English letters.consider the following relations on S and determine whether (a)R1 = {(a,b)|a and b have no letters in common} is reflexive or not 我想問這個選項..no letters in common是指什麼樣的字.. ------------------------------------------------------------------ 97政大資科 Let A be the set of all bit strings of length 11. Define an equivalence relation R on A with the condition that xRy iff bits x and y have the same number of 1's.Then (b)The quotient set A/R has ____ equivalence classes 我想問其中A/R是代表什麼.. 不好意思問題有點多..希望高手能給小弟我一些指教 謝謝:) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 1.169.173.40 ※ 編輯: ceo890710 來自: 1.169.173.40 (08/07 21:25) ※ 編輯: ceo890710 來自: 1.169.173.40 (08/07 21:26)

08/07 21:27, , 1F
台大資工那兩題應該都是true
08/07 21:27, 1F
※ 編輯: ceo890710 來自: 1.169.173.40 (08/07 21:33)

08/07 21:34, , 2F
(d)我剛查過瞭解了~我想問(e)是為什麼呢..
08/07 21:34, 2F

08/07 21:38, , 3F
97台大資工的(e)因為topological sort不一定唯一
08/07 21:38, 3F

08/07 21:39, , 4F
97清大資工 照題意 不具reflexive
08/07 21:39, 4F

08/08 11:11, , 5F
97清大, no letter in common --> a,b中沒有任何一個字
08/08 11:11, 5F

08/08 11:11, , 6F
元相同
08/08 11:11, 6F
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