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Groups > comp.lang.python > #106757
| From | Mark Lawrence <breamoreboy@yahoo.co.uk> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Find the number of robots needed to walk through the rectangular grid |
| Date | 2016-04-09 20:23 +0100 |
| Message-ID | <mailman.137.1460229825.2253.python-list@python.org> (permalink) |
| References | <8c570da8-ab31-44f3-9fdf-83e28741ffe4@googlegroups.com> <CALwzidkhCO0bK2XxP-BZ=aPxuSX-ZiSxq_Yn7pe+ehV8qTsN8Q@mail.gmail.com> <mailman.129.1460220245.2253.python-list@python.org> <e42777b0-fc2b-4f2c-8c2b-a53b41bfe3f7@googlegroups.com> <nebkro$8j2$1@ger.gmane.org> |
On 09/04/2016 18:13, Joe wrote: > On Saturday, 9 April 2016 18:44:20 UTC+2, Ian wrote: >> On Sat, Apr 9, 2016 at 8:18 AM, Joe wrote: >>> How to find the number of robots needed to walk through the rectangular grid >>> The movement of a robot in the field is divided into successive steps >>> >>> In one step a robot can move either horizontally or vertically (in one row or in one column of cells) by some number of cells >>> >>> A robot can move in one step from cell X to cell Y if and only if the distance between the centers of the cells X and Y is equal to the sum of integers contained in X and Y >>> >>> Cell X is reachable for robot A if either A is currently standing in the cell X or A can reach X after some number of steps. During the transfer the robot can choose the direction (horizontal or vertical) of each step arbitrarily >>> [![enter image description here][1]][1] >>> >>> I started implementing it by first checking the row and print the index of the Cell X and Y where the distance is equal to the sum of integers contained in X and Y >>> >>> but after coding I found it difficult to remember the index when moving vertically >>> >>> So I thought to Build a graph where nodes are grid cells and edges are legal direct movements, then run any connected components algorithm to find which cells are reachable from each other >>> >>> >>> Can anyone implement it with graphs or queue? >> >> I'd use a disjoint-set data structure. The number of robots needed is >> equal to the number of disjoint subsets. >> >> https://en.wikipedia.org/wiki/Disjoint-set_data_structure > > Could you post a formal solution of disjoint-set using my algorithm > You write the code, we comment on it. No code, no comment. Got the message? -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence
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Find the number of robots needed to walk through the rectangular grid Joe <lildinho14@gmail.com> - 2016-04-09 07:18 -0700
Re: Find the number of robots needed to walk through the rectangular grid Ian Kelly <ian.g.kelly@gmail.com> - 2016-04-09 10:43 -0600
Re: Find the number of robots needed to walk through the rectangular grid Joe <lildinho14@gmail.com> - 2016-04-09 10:13 -0700
Re: Find the number of robots needed to walk through the rectangular grid Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2016-04-09 15:10 -0400
Re: Find the number of robots needed to walk through the rectangular grid Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-04-09 20:23 +0100
Re: Find the number of robots needed to walk through the rectangular grid Joe <lildinho14@gmail.com> - 2016-04-09 12:41 -0700
Re: Find the number of robots needed to walk through the rectangular grid Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-04-09 20:55 +0100
Re: Find the number of robots needed to walk through the rectangular grid Joe <lildinho14@gmail.com> - 2016-04-09 14:28 -0700
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