[理工][DS] 台大電機98 第12題

看板Grad-ProbAsk作者 (JOU)時間12年前 (2012/01/31 20:43), 編輯推噓2(209)
留言11則, 5人參與, 最新討論串1/1
Any undirected graph with n nodes and n-1 edges, where n>=1, is a tree 找到的答案是說false 但想半天想不出來是圖長怎樣會出錯 Note: Graphs A graph does not contain self-circular edges, e.g.,(u,u),nor multiple edges between two nodes, i.e., at most one entry (u,v) in E for each distinct u and v -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.106.241

01/31 22:07, , 1F
若graph為unconnected有兩個components其一為4個點且
01/31 22:07, 1F

01/31 22:08, , 2F
四個邊有cycle另一為孤立點則 |E|=|V|-1 但不為tree
01/31 22:08, 2F

02/01 00:54, , 3F
加上connected的條件才會對
02/01 00:54, 3F

02/01 01:01, , 4F
因單獨一個點也能視為為無相圖 所以可以畫出:
02/01 01:01, 4F

02/01 01:02, , 5F
●一●
02/01 01:02, 5F

02/01 01:03, , 6F
\ /
02/01 01:03, 6F

02/01 01:03, , 7F
● ●
02/01 01:03, 7F

02/01 01:03, , 8F
02/01 01:03, 8F

02/01 01:04, , 9F
所以N=4 E=3 可是因為無Connected 所以不是tree 同3f
02/01 01:04, 9F

02/01 01:27, , 10F
原來如此
02/01 01:27, 10F

09/11 14:50, , 11F
09/11 14:50, 11F
文章代碼(AID): #1F9-7OU_ (Grad-ProbAsk)