Longest Simple Path - Intro to Algorithms Udacity English Japanese

Longest Simple Path - Intro to AlgorithmsYouTube↗ IA↗(long shot)
Education 17.4K views 32 likes 27 dislikes 23 Feb 2015

Udacity 651K subscribers United States YouTube↗

Click to Play Video

All right, to introduce this concept, it's going to help to have another definition that I haven't given you yet.

決定問題の概念を紹介するにあたりまだご紹介していない新しい定義を使いましょう

So here's a graph, we have been talking about things like shortest paths.

ここにグラフがあります今まで最短経路の話をしてきました

So let's look at a path from a to g. So here's a natural path to choose.

aからgまでのパスを見ましょう普通はこのパスを選びますよね

It's one of the shortest paths from a to g, but it's by no means the only path from a to g.

aからgまでの最短経路ですがパスは他にもあります

So here's another path from a to g. a to b to e to d to a to b to e to g. It's a path.

他にはa、b、e、d、a、b、e、dの順番を通るパスがあります

It's going from node to node crossing edges but it's not a simple path.

しかしこれは最短経路ではありません

So simple path is not allowed to have any repeated nodes.

単純路は同じノードを通りません

Any shortest path is going to be a simple path. Right. Why?

最短経路は単純路になりますなぜでしょうか

Because if we had any repeats along the way from a to g,

aからgの道でリピートがあれば

if we visit b and then sometime later we go back to b then there's going to be a path

まずbを通りその後またbを通ることになります

that just goes from a to b and then using this path from b to g.

aからbへ bからgへ行くので

We don't need any of these links in between.

この間のリンクは必要ありません

So if the shortest path actually had on it a repeat, it was not simple path,

最短経路にリピートがあればそれは単純路ではありません

then it can't be a shortest path, there must be a shorter path still, so that's a contradiction.

つまり最短経路であるべきなのに違うという矛盾が生じます

Now the longest simple path that you can have, can have it most

最長の単純路はnノードを持ちますが

n nodes on it because there is only n nodes in the graph and we're not allowed to repeat any.

nノードをリピートすることは許されていません

So the longest simple path is at link n. This graph has seven nodes.

つまり最長の単純路のリンクはｎになりますこのグラフには7個のノードがあります

So let's ask the question having to do with this graph here.

このグラフを使った問題です

I want you to check each box with number K next to it

数字のkとチェック用のボックスを用意しました

if there's a simple path of K nodes that goes from a to g.

aからgへまでのノードがk個となる単経路を確認していきましょう

So for example, it can't be one beacause it has to have at least a and g on it,

aからgまで通る必要があるため少なくとも1にはなりませんね

and we already solved path a, b, e, g that's a simple path that has four nodes on it, so I'll give you four.

すでにa、b、e、gを通って4つのノードがあるので 4は大丈夫ですね

For each possible length, check the box if there is a simple path

このようにしてaからgまで通るのにノードの数だけの単純路が存在するのか

with that number of nodes on it from a to g.

ボックスにチェックを入れてみてください

Similar videos:

Top K Code - Intro to Algorithms
Udacity
722 views 2 likes 0 dislikes 19 Jul 2012100% match

大诚子白捡了一根羊蝎子，回家做个酱香羊蝎子，一家三口啃过瘾！【爱吃的大诚子】
Xiao Hai and his Sugar Glider
5.5K views 143 likes 10 dislikes 16 Mar 202154% match

Ink jet cartridge leaking ink after refill: how to fix
viandant5
127.9K views 331 likes 38 dislikes 10 Nov 201452% match

【小胖在西北】天气太冷了，小胖在家做热乎乎的番茄肥牛面，泡面杀手，太舒服了
 Family in northwest China
16.2K views 394 likes 14 dislikes 24 Oct 202052% match

How to Make Spring Vibration/Motion Sensor! | DIY | Homemade
NematicsLab
98.1K views 807 likes 383 dislikes 21 Apr 202051% match

3斤猪皮，大诚子做“猪皮冻”，晶莹剔透又筋道，蘸着辣椒吃真过瘾！【爱吃的大诚子】
Xiao Hai and his Sugar Glider
3K views 70 likes 7 dislikes 14 Dec 202051% match

满月后难得天气好，带一可出门去逛一逛，宁宁也要当一回小宝宝
 酒鬼小莉 Drunkard Lee
146.2K views 3.9K likes 104 dislikes 12 Mar 202151% match

Parsley Tea to Help You Lose Weight and Reduce Water Retention
Natural Cures
504.8K views 8.1K likes 122 dislikes 16 Nov 201651% match

How to do the reverse pendulum service in table tennis?
pingponged TV
70.2K views 1.1K likes 14 dislikes 20 Jan 202151% match

다리 꺾인 길냥이 '지나'의 묘생역전?!
SBS TV동물농장x애니멀봐
3.8M views 35.1K likes 607 dislikes 03 Dec 201750% match

Vaginal Yeast Infection: Treatment & prevention by Dr Astha Dayal (Gynaecologist) | 1mg
Tata 1mg
652.3K views 3.2K likes -1 dislikes 16 Oct 201850% match

너 아픈데도 이렇게 귀엽기 있냐ㅣAxolotl, you’re cute even when you’re sick
SBS TV동물농장x애니멀봐
3.4M views 34.2K likes -1 dislikes 13 Jan 201950% match

débarrassez vous naturellement de l'excès de graisse avec cette astuce
Rose Moony
524.9K views 0 likes -1 dislikes 20 Feb 201950% match

How to Make a Wrap Dress | Teach Me Fashion
TeachMeFashion
111.2K views 633 likes 40 dislikes 16 May 201450% match

快要回乡过年了，胖哥组织全家大扫除，一起动手忙得不亦乐乎~【胖哥有杜】
Fat brother has Du
18.5K views 460 likes 10 dislikes 05 Feb 202150% match

海水退潮後，小倪趕海撬生蠔，直接撬到一大桶生蠔回家吃【小倪趕海】
Xiao Ni Ganhai
2.7K views 60 likes 2 dislikes 04 Nov 202050% match

✔ Minecraft: 10 Things to Make With Banners
MagmaMusen
2.5M views 36.3K likes 607 dislikes 27 Oct 201550% match

How to Gameshare on Xbox One
FatedCb
189.8K views 744 likes 64 dislikes 15 Mar 201450% match

How to Connect Stove to Gas
Reparacion Mantenimiento de PC
99.9K views 373 likes 83 dislikes 25 Aug 201750% match

26元買條五花肉，圓子做紅燒肉不一樣的吃法，大塊吃肉，拌著米飯真過癮！【圓圓食記】
菲菲故事屋
3.5K views 81 likes -1 dislikes 09 Jan 202150% match

외발자전거 타고 백발백중! 호크아이 로빈훗 다 나와~!┃A boy who never misses the target while riding an unicycle!
우와한 비디오
1.1M views 5.9K likes -1 dislikes 15 Jun 201950% match

Chinese beauty captain unarmed the bomb to save the beautiful hunter！Hunter soldier 21
StarTrack Drama Studio
2.6M views 6.8K likes -1 dislikes 20 Sep 201950% match

ep245 unit13 15 l optional reading
Udacity
2.5K views 3 likes 0 dislikes 18 Oct 201250% match

大sao下馆子，48元的铁锅牛肉焖面配腐竹汤，老板娘吃蒜厉害了
 Xu Dasao
426.9K views 2.5K likes 267 dislikes 17 Jun 201950% match

How To Make A Simple, Natural Alternative To Bleach
Natural Cures
10.2K views 915 likes 10 dislikes 29 Nov 202049% match

0 views 0 likes 0 dislikes 04 Jun 202649% match

【赶海二哥】深夜赶海大爆桶！螃蟹、海螺全都冒头，二哥一夹子下去就有货
 Yunbao Animation
1.3K views 45 likes 2 dislikes 30 Oct 202049% match

How to Lose Weight Fast With Cucumber and Banana! No Strict Diet No Workout!
Recommended Presh TV
264.3K views 4K likes 208 dislikes 08 Jan 202149% match

DCS战争模拟12：鹰酱内战，8架F22战斗机，遭遇30架F35！最后结局会如何？#大香蕉游戏
 Big Banana Game
2.5K views 50 likes 3 dislikes 19 Jan 202149% match

RUSPITIELLI Dell'Irpinia 😍 Incredibile Dolcetto Di Carnevale
Le ricette di zia Franca
17.5K views 697 likes 13 dislikes 27 Jan 202149% match

Settings Privacy About Contact Donate