9x9 Map Path: In and out next to each other?The robotic vacuum cleanerMosaic with tetris blocksStaking Out the IntegersHelp! I've forgotten my phone's lock pattern!Block the snake from reaching pointsThis ant sure is smart. But how fast is it?Squaring a crossPheno Menon and his coloured flagsCreate a map of a game's portalsLight Amplification by Stimulated Emission of Radiation

Why did the person in charge of a principality not just declare themself king?

Is there a simple example that empirical evidence is misleading?

Is it legal to have an abortion in another state or abroad?

Is there a context where the expression `a.b::c` makes sense?

Why would a rational buyer offer to buy with no conditions precedent?

Do photons bend spacetime or not?

Security vulnerabilities of POST over SSL

Gravitational Force Between Numbers

How was Daenerys able to legitimise this character?

How to deal with a colleague who is being aggressive?

Why is unzipped directory exactly 4.0k (much smaller than zipped file)?

SFDX: where can set Field-level security and accessibility?

Why isn't 'chemically-strengthened glass' made with potassium carbonate to begin with?

What does kpsewhich stand for?

Time complexity of an algorithm: Is it important to state the base of the logarithm?

WordPress 5.2.1 deactivated my jQuery

Grade-school elementary algebra presented in an abstract-algebra style?

How did NASA Langley end up with the first 737?

Shorten or merge multiple lines of `&> /dev/null &`

Natural Armour and Weapons

Why A=2 and B=1 in the call signs for Spirit and Opportunity?

Need to read my home electrical Meter

Can a person survive on blood in place of water?

ESTA validity after a visa denial



9x9 Map Path: In and out next to each other?


The robotic vacuum cleanerMosaic with tetris blocksStaking Out the IntegersHelp! I've forgotten my phone's lock pattern!Block the snake from reaching pointsThis ant sure is smart. But how fast is it?Squaring a crossPheno Menon and his coloured flagsCreate a map of a game's portalsLight Amplification by Stimulated Emission of Radiation













5












$begingroup$


This isn't something I read in a book or anything, it's more of a puzzle I thought up for myself.



However, I am unable to find a solution.



Here's my problem:



If I create a 9x9 checkerboard, and want to walk a path across it, where each block is walked upon only once, and there are only 90° turns, it's easy enough to create any path. (See first image example:)



enter image description here



However, if I want to create an entrance and exit point NEXT TO EACH OTHER, I am stumped. I can't do it:



enter image description here



Can someone help me think of a path ac cross a 9x9 area, where the entrance and exit points are directly next to each other, and yet each block is used only once and only 90° turns are used?



Thanks again.










share|improve this question







New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






$endgroup$







  • 2




    $begingroup$
    From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
    $endgroup$
    – Rewan Demontay
    5 hours ago






  • 1




    $begingroup$
    I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
    $endgroup$
    – Adam
    5 hours ago















5












$begingroup$


This isn't something I read in a book or anything, it's more of a puzzle I thought up for myself.



However, I am unable to find a solution.



Here's my problem:



If I create a 9x9 checkerboard, and want to walk a path across it, where each block is walked upon only once, and there are only 90° turns, it's easy enough to create any path. (See first image example:)



enter image description here



However, if I want to create an entrance and exit point NEXT TO EACH OTHER, I am stumped. I can't do it:



enter image description here



Can someone help me think of a path ac cross a 9x9 area, where the entrance and exit points are directly next to each other, and yet each block is used only once and only 90° turns are used?



Thanks again.










share|improve this question







New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






$endgroup$







  • 2




    $begingroup$
    From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
    $endgroup$
    – Rewan Demontay
    5 hours ago






  • 1




    $begingroup$
    I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
    $endgroup$
    – Adam
    5 hours ago













5












5








5


1



$begingroup$


This isn't something I read in a book or anything, it's more of a puzzle I thought up for myself.



However, I am unable to find a solution.



Here's my problem:



If I create a 9x9 checkerboard, and want to walk a path across it, where each block is walked upon only once, and there are only 90° turns, it's easy enough to create any path. (See first image example:)



enter image description here



However, if I want to create an entrance and exit point NEXT TO EACH OTHER, I am stumped. I can't do it:



enter image description here



Can someone help me think of a path ac cross a 9x9 area, where the entrance and exit points are directly next to each other, and yet each block is used only once and only 90° turns are used?



Thanks again.










share|improve this question







New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






$endgroup$




This isn't something I read in a book or anything, it's more of a puzzle I thought up for myself.



However, I am unable to find a solution.



Here's my problem:



If I create a 9x9 checkerboard, and want to walk a path across it, where each block is walked upon only once, and there are only 90° turns, it's easy enough to create any path. (See first image example:)



enter image description here



However, if I want to create an entrance and exit point NEXT TO EACH OTHER, I am stumped. I can't do it:



enter image description here



Can someone help me think of a path ac cross a 9x9 area, where the entrance and exit points are directly next to each other, and yet each block is used only once and only 90° turns are used?



Thanks again.







pattern geometry






share|improve this question







New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.










share|improve this question







New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








share|improve this question




share|improve this question






New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








asked 5 hours ago









etsnymanetsnyman

1283




1283




New contributor



etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




New contributor




etsnyman is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









  • 2




    $begingroup$
    From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
    $endgroup$
    – Rewan Demontay
    5 hours ago






  • 1




    $begingroup$
    I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
    $endgroup$
    – Adam
    5 hours ago












  • 2




    $begingroup$
    From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
    $endgroup$
    – Rewan Demontay
    5 hours ago






  • 1




    $begingroup$
    I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
    $endgroup$
    – Adam
    5 hours ago







2




2




$begingroup$
From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
$endgroup$
– Rewan Demontay
5 hours ago




$begingroup$
From a glance I believe that it is impossible to do, but I have no proof other then just my intuition.
$endgroup$
– Rewan Demontay
5 hours ago




1




1




$begingroup$
I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
$endgroup$
– Adam
5 hours ago




$begingroup$
I also think that it is impossible to do. From the appearance of the problem I think that there will be an elegant mathematical proof
$endgroup$
– Adam
5 hours ago










1 Answer
1






active

oldest

votes


















6












$begingroup$

It’s not possible.



Moving (stepping) only horizontally or vertically
(never moving diagonally or jumping over squares),
successive steps are always on squares of alternate colors. 
For example, in your first illustration, the first step is blue,
the second is pink, the third is blue again, and so on. 
In general, the odd-numbered steps are blue
and the even-numbered steps are pink.



Since both dimensions of your board are odd (9),
the total size is odd (9×9=81),
and so the last step, the 81st, is an odd number. 
Therefore, it must be the same color as the first square
(as seen in your first illustration). 
And, since adjacent (next-to-each-other) squares
are always different colors,
the exit square on an odd-sized board
cannot be next to the entrance square.






share|improve this answer









$endgroup$












  • $begingroup$
    Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
    $endgroup$
    – etsnyman
    4 hours ago











Your Answer








StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "559"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);






etsnyman is a new contributor. Be nice, and check out our Code of Conduct.









draft saved

draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f84242%2f9x9-map-path-in-and-out-next-to-each-other%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









6












$begingroup$

It’s not possible.



Moving (stepping) only horizontally or vertically
(never moving diagonally or jumping over squares),
successive steps are always on squares of alternate colors. 
For example, in your first illustration, the first step is blue,
the second is pink, the third is blue again, and so on. 
In general, the odd-numbered steps are blue
and the even-numbered steps are pink.



Since both dimensions of your board are odd (9),
the total size is odd (9×9=81),
and so the last step, the 81st, is an odd number. 
Therefore, it must be the same color as the first square
(as seen in your first illustration). 
And, since adjacent (next-to-each-other) squares
are always different colors,
the exit square on an odd-sized board
cannot be next to the entrance square.






share|improve this answer









$endgroup$












  • $begingroup$
    Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
    $endgroup$
    – etsnyman
    4 hours ago















6












$begingroup$

It’s not possible.



Moving (stepping) only horizontally or vertically
(never moving diagonally or jumping over squares),
successive steps are always on squares of alternate colors. 
For example, in your first illustration, the first step is blue,
the second is pink, the third is blue again, and so on. 
In general, the odd-numbered steps are blue
and the even-numbered steps are pink.



Since both dimensions of your board are odd (9),
the total size is odd (9×9=81),
and so the last step, the 81st, is an odd number. 
Therefore, it must be the same color as the first square
(as seen in your first illustration). 
And, since adjacent (next-to-each-other) squares
are always different colors,
the exit square on an odd-sized board
cannot be next to the entrance square.






share|improve this answer









$endgroup$












  • $begingroup$
    Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
    $endgroup$
    – etsnyman
    4 hours ago













6












6








6





$begingroup$

It’s not possible.



Moving (stepping) only horizontally or vertically
(never moving diagonally or jumping over squares),
successive steps are always on squares of alternate colors. 
For example, in your first illustration, the first step is blue,
the second is pink, the third is blue again, and so on. 
In general, the odd-numbered steps are blue
and the even-numbered steps are pink.



Since both dimensions of your board are odd (9),
the total size is odd (9×9=81),
and so the last step, the 81st, is an odd number. 
Therefore, it must be the same color as the first square
(as seen in your first illustration). 
And, since adjacent (next-to-each-other) squares
are always different colors,
the exit square on an odd-sized board
cannot be next to the entrance square.






share|improve this answer









$endgroup$



It’s not possible.



Moving (stepping) only horizontally or vertically
(never moving diagonally or jumping over squares),
successive steps are always on squares of alternate colors. 
For example, in your first illustration, the first step is blue,
the second is pink, the third is blue again, and so on. 
In general, the odd-numbered steps are blue
and the even-numbered steps are pink.



Since both dimensions of your board are odd (9),
the total size is odd (9×9=81),
and so the last step, the 81st, is an odd number. 
Therefore, it must be the same color as the first square
(as seen in your first illustration). 
And, since adjacent (next-to-each-other) squares
are always different colors,
the exit square on an odd-sized board
cannot be next to the entrance square.







share|improve this answer












share|improve this answer



share|improve this answer










answered 4 hours ago









Peregrine RookPeregrine Rook

4,79821939




4,79821939











  • $begingroup$
    Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
    $endgroup$
    – etsnyman
    4 hours ago
















  • $begingroup$
    Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
    $endgroup$
    – etsnyman
    4 hours ago















$begingroup$
Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
$endgroup$
– etsnyman
4 hours ago




$begingroup$
Thanks. I guessed so, but I wasn't sure. Thanks for confirming it!
$endgroup$
– etsnyman
4 hours ago










etsnyman is a new contributor. Be nice, and check out our Code of Conduct.









draft saved

draft discarded


















etsnyman is a new contributor. Be nice, and check out our Code of Conduct.












etsnyman is a new contributor. Be nice, and check out our Code of Conduct.











etsnyman is a new contributor. Be nice, and check out our Code of Conduct.














Thanks for contributing an answer to Puzzling Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid


  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.

Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f84242%2f9x9-map-path-in-and-out-next-to-each-other%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

19. јануар Садржај Догађаји Рођења Смрти Празници и дани сећања Види још Референце Мени за навигацијуу

Israel Cuprins Etimologie | Istorie | Geografie | Politică | Demografie | Educație | Economie | Cultură | Note explicative | Note bibliografice | Bibliografie | Legături externe | Meniu de navigaresite web oficialfacebooktweeterGoogle+Instagramcanal YouTubeInstagramtextmodificaremodificarewww.technion.ac.ilnew.huji.ac.ilwww.weizmann.ac.ilwww1.biu.ac.ilenglish.tau.ac.ilwww.haifa.ac.ilin.bgu.ac.ilwww.openu.ac.ilwww.ariel.ac.ilCIA FactbookHarta Israelului"Negotiating Jerusalem," Palestine–Israel JournalThe Schizoid Nature of Modern Hebrew: A Slavic Language in Search of a Semitic Past„Arabic in Israel: an official language and a cultural bridge”„Latest Population Statistics for Israel”„Israel Population”„Tables”„Report for Selected Countries and Subjects”Human Development Report 2016: Human Development for Everyone„Distribution of family income - Gini index”The World FactbookJerusalem Law„Israel”„Israel”„Zionist Leaders: David Ben-Gurion 1886–1973”„The status of Jerusalem”„Analysis: Kadima's big plans”„Israel's Hard-Learned Lessons”„The Legacy of Undefined Borders, Tel Aviv Notes No. 40, 5 iunie 2002”„Israel Journal: A Land Without Borders”„Population”„Israel closes decade with population of 7.5 million”Time Series-DataBank„Selected Statistics on Jerusalem Day 2007 (Hebrew)”Golan belongs to Syria, Druze protestGlobal Survey 2006: Middle East Progress Amid Global Gains in FreedomWHO: Life expectancy in Israel among highest in the worldInternational Monetary Fund, World Economic Outlook Database, April 2011: Nominal GDP list of countries. Data for the year 2010.„Israel's accession to the OECD”Popular Opinion„On the Move”Hosea 12:5„Walking the Bible Timeline”„Palestine: History”„Return to Zion”An invention called 'the Jewish people' – Haaretz – Israel NewsoriginalJewish and Non-Jewish Population of Palestine-Israel (1517–2004)ImmigrationJewishvirtuallibrary.orgChapter One: The Heralders of Zionism„The birth of modern Israel: A scrap of paper that changed history”„League of Nations: The Mandate for Palestine, 24 iulie 1922”The Population of Palestine Prior to 1948originalBackground Paper No. 47 (ST/DPI/SER.A/47)History: Foreign DominationTwo Hundred and Seventh Plenary Meeting„Israel (Labor Zionism)”Population, by Religion and Population GroupThe Suez CrisisAdolf EichmannJustice Ministry Reply to Amnesty International Report„The Interregnum”Israel Ministry of Foreign Affairs – The Palestinian National Covenant- July 1968Research on terrorism: trends, achievements & failuresThe Routledge Atlas of the Arab–Israeli conflict: The Complete History of the Struggle and the Efforts to Resolve It"George Habash, Palestinian Terrorism Tactician, Dies at 82."„1973: Arab states attack Israeli forces”Agranat Commission„Has Israel Annexed East Jerusalem?”original„After 4 Years, Intifada Still Smolders”From the End of the Cold War to 2001originalThe Oslo Accords, 1993Israel-PLO Recognition – Exchange of Letters between PM Rabin and Chairman Arafat – Sept 9- 1993Foundation for Middle East PeaceSources of Population Growth: Total Israeli Population and Settler Population, 1991–2003original„Israel marks Rabin assassination”The Wye River Memorandumoriginal„West Bank barrier route disputed, Israeli missile kills 2”"Permanent Ceasefire to Be Based on Creation Of Buffer Zone Free of Armed Personnel Other than UN, Lebanese Forces"„Hezbollah kills 8 soldiers, kidnaps two in offensive on northern border”„Olmert confirms peace talks with Syria”„Battleground Gaza: Israeli ground forces invade the strip”„IDF begins Gaza troop withdrawal, hours after ending 3-week offensive”„THE LAND: Geography and Climate”„Area of districts, sub-districts, natural regions and lakes”„Israel - Geography”„Makhteshim Country”Israel and the Palestinian Territories„Makhtesh Ramon”„The Living Dead Sea”„Temperatures reach record high in Pakistan”„Climate Extremes In Israel”Israel in figures„Deuteronom”„JNF: 240 million trees planted since 1901”„Vegetation of Israel and Neighboring Countries”Environmental Law in Israel„Executive branch”„Israel's election process explained”„The Electoral System in Israel”„Constitution for Israel”„All 120 incoming Knesset members”„Statul ISRAEL”„The Judiciary: The Court System”„Israel's high court unique in region”„Israel and the International Criminal Court: A Legal Battlefield”„Localities and population, by population group, district, sub-district and natural region”„Israel: Districts, Major Cities, Urban Localities & Metropolitan Areas”„Israel-Egypt Relations: Background & Overview of Peace Treaty”„Solana to Haaretz: New Rules of War Needed for Age of Terror”„Israel's Announcement Regarding Settlements”„United Nations Security Council Resolution 497”„Security Council resolution 478 (1980) on the status of Jerusalem”„Arabs will ask U.N. to seek razing of Israeli wall”„Olmert: Willing to trade land for peace”„Mapping Peace between Syria and Israel”„Egypt: Israel must accept the land-for-peace formula”„Israel: Age structure from 2005 to 2015”„Global, regional, and national disability-adjusted life years (DALYs) for 306 diseases and injuries and healthy life expectancy (HALE) for 188 countries, 1990–2013: quantifying the epidemiological transition”10.1016/S0140-6736(15)61340-X„World Health Statistics 2014”„Life expectancy for Israeli men world's 4th highest”„Family Structure and Well-Being Across Israel's Diverse Population”„Fertility among Jewish and Muslim Women in Israel, by Level of Religiosity, 1979-2009”„Israel leaders in birth rate, but poverty major challenge”„Ethnic Groups”„Israel's population: Over 8.5 million”„Israel - Ethnic groups”„Jews, by country of origin and age”„Minority Communities in Israel: Background & Overview”„Israel”„Language in Israel”„Selected Data from the 2011 Social Survey on Mastery of the Hebrew Language and Usage of Languages”„Religions”„5 facts about Israeli Druze, a unique religious and ethnic group”„Israël”Israel Country Study Guide„Haredi city in Negev – blessing or curse?”„New town Harish harbors hopes of being more than another Pleasantville”„List of localities, in alphabetical order”„Muncitorii români, doriți în Israel”„Prietenia româno-israeliană la nevoie se cunoaște”„The Higher Education System in Israel”„Middle East”„Academic Ranking of World Universities 2016”„Israel”„Israel”„Jewish Nobel Prize Winners”„All Nobel Prizes in Literature”„All Nobel Peace Prizes”„All Prizes in Economic Sciences”„All Nobel Prizes in Chemistry”„List of Fields Medallists”„Sakharov Prize”„Țara care și-a sfidat "destinul" și se bate umăr la umăr cu Silicon Valley”„Apple's R&D center in Israel grew to about 800 employees”„Tim Cook: Apple's Herzliya R&D center second-largest in world”„Lecții de economie de la Israel”„Land use”Israel Investment and Business GuideA Country Study: IsraelCentral Bureau of StatisticsFlorin Diaconu, „Kadima: Flexibilitate și pragmatism, dar nici un compromis în chestiuni vitale", în Revista Institutului Diplomatic Român, anul I, numărul I, semestrul I, 2006, pp. 71-72Florin Diaconu, „Likud: Dreapta israeliană constant opusă retrocedării teritoriilor cureite prin luptă în 1967", în Revista Institutului Diplomatic Român, anul I, numărul I, semestrul I, 2006, pp. 73-74MassadaIsraelul a crescut in 50 de ani cât alte state intr-un mileniuIsrael Government PortalIsraelIsraelIsraelmmmmmXX451232cb118646298(data)4027808-634110000 0004 0372 0767n7900328503691455-bb46-37e3-91d2-cb064a35ffcc1003570400564274ge1294033523775214929302638955X146498911146498911

Кастелфранко ди Сопра Становништво Референце Спољашње везе Мени за навигацију43°37′18″ СГШ; 11°33′32″ ИГД / 43.62156° СГШ; 11.55885° ИГД / 43.62156; 11.5588543°37′18″ СГШ; 11°33′32″ ИГД / 43.62156° СГШ; 11.55885° ИГД / 43.62156; 11.558853179688„The GeoNames geographical database”„Istituto Nazionale di Statistica”проширитиууWorldCat156923403n850174324558639-1cb14643287r(подаци)