Day 8

input/08-test.txt

@@ -0,0 +1,10 @@
+be cfbegad cbdgef fgaecd cgeb fdcge agebfd fecdb fabcd edb | fdgacbe cefdb cefbgd gcbe
+edbfga begcd cbg gc gcadebf fbgde acbgfd abcde gfcbed gfec | fcgedb cgb dgebacf gc
+fgaebd cg bdaec gdafb agbcfd gdcbef bgcad gfac gcb cdgabef | cg cg fdcagb cbg
+fbegcd cbd adcefb dageb afcb bc aefdc ecdab fgdeca fcdbega | efabcd cedba gadfec cb
+aecbfdg fbg gf bafeg dbefa fcge gcbea fcaegb dgceab fcbdga | gecf egdcabf bgf bfgea
+fgeab ca afcebg bdacfeg cfaedg gcfdb baec bfadeg bafgc acf | gebdcfa ecba ca fadegcb
+dbcfg fgd bdegcaf fgec aegbdf ecdfab fbedc dacgb gdcebf gf | cefg dcbef fcge gbcadfe
+bdfegc cbegaf gecbf dfcage bdacg ed bedf ced adcbefg gebcd | ed bcgafe cdgba cbgef
+egadfb cdbfeg cegd fecab cgb gbdefca cg fgcdab egfdb bfceg | gbdfcae bgc cg cgb
+gcafb gcf dcaebfg ecagb gf abcdeg gaef cafbge fdbac fegbdc | fgae cfgab fg bagce

input/08.txt

@@ -0,0 +1,200 @@
+cfgeda afcbg fbcdaeg gbdfa fdgcba cbdf becga cf gcf gbdefa | bfcd acgdfe cfabg dcbf
+ge gbafde gbafc bfagdc cdebf fabegc egbfc ebg dbgacfe ecga | bge cfabdge fgeabc gcea
+dce ecdbfa bacdg gfdabc egda gecbd ed dcabge bgecf cgadbef | eabfdc degacb ecfbg cgedb
+bdae bfcedg gecadf gdaefcb bfcag egafb fdbeag edgfb ea eaf | gedbf abed bcafg gdfbe
+cefgdab ba efdacb gfeabd abfg cagedf bcged eba egadb fdeag | eab afgb afgb fdeag
+fecbdg edcgba cef gfacbde ebfa fcbead acdeb cfdag ef dafec | adcef ef fe fadgc
+agefb dbfgca dfgea afgcde cfdbea agcfd gced def ed fbgedac | ed dgecafb cabdgf fed
+gcafed ecabd bfa fdaebg bf febg efdba fgacdb aedfg dagecfb | defgacb bf bf dfeag
+gcfabe gbdc bgdacfe gbecdf ebgfc bcdfe dc degfca ced befad | bdgfeca dceagf cefdga ebdfa
+cfaeb bafg bcg dgefc fcbeg gb defcbag eafgbc adcebg cdbafe | bfag afgb gbc cgfeb
+agcef fgdbeca bc efagbd cfbea cebfda bfdea dbac ebc gcefbd | acfge ecabf acdb bc
+dacfbeg cegfb aecf cegbd fabdge bgafe agbcdf bfgcae fc gcf | cabdgf efcbg bgecf gdeacfb
+daebg cgdabe afgde fbagcd eb cbagd baefcgd edb dcaefb bgec | edb begc egdacb eb
+dbcfea dbfac adg gbac dbeagf bgafdc bdaegcf gdafc ga cgfde | ebdafg gacb agd dga
+gcdf cda ebagfd egcfbda cbega aegdf eadcgf bcedfa eacgd dc | dcgfae cda bfgcaed acbeg
+gcdbea cf dgeac gacefd bgcdfa fegc beafd fcd decaf egfdcba | geacdb cf gfec egfadc
+aced fedcg efa cfgdeb fcadeg afcbge efadg ae bgecfad gdfba | fegacb bcagedf geacbf eadc
+fdegca faedcb aecgd cfgde cef fe fgcbd fgea ebgdac bfeadgc | cgade dfgec fe fe
+egdbac dbfcga egfadbc abe dcae dgfbe ae gabed bgcad acegbf | efabgc bdcag aeb gadcb
+da dca dbfeagc gcdfb dage eagbc adcbg fadbce badegc ebfcag | gcabde egfcab adc dca
+ecabd gc cbg befadc egdacfb edbfg edbgc cbeagf beadgc agcd | eacdb gcebd cadg cdeba
+gcfdae bdgcefa acbge edbfgc aegdcb gdceb bdae cagfb cea ea | ecagdbf dbecg gbced dcageb
+gdac gd ecbgdfa dagbe ebdgcf baecd begaf deg bdgace ecdabf | ebafg cdga dg dg
+ca decabf dbgae ace dbacfeg cbafge ecbdgf defbc dbcea adfc | dabec bcdfe egbcadf eca
+gfaed dgbaec gbf bf cfegba fgabd cfdb adgcfb dbcag dgacbfe | fcdb acbgd fdagb gbf
+dceagf cge dbgacf eg fged afcdg eadcg cbgeaf cdfgaeb ebdac | gce cge agcedbf fadcg
+cfbae edafc cb fbc fegab cfegdb dabc bfcdega efbadc deacfg | cedfa gdefbc adcb cfb
+afbgdc acgbed gdae eabcf cda da gbcde bdcea gdacbef dgcbfe | aedg bcgde bfgdca da
+gdbfaec aebcg egacf bcgd cegadb ebc badge aebfgd bc bfdaec | ebc bc fgace bc
+fa cdeab fegbda beadcg gfedc cfade facb adcgbef fad dcebaf | dbgecfa dafcbeg cbadge cbead
+egacf bdegfa df daf cbaged bgdf efbcad cebafdg daegf dbeag | badeg dbcgaef gedaf ebagcd
+dcagbf gceba ecgadf dfeb cef afceb ef cebfda adcebfg afdbc | ef bcadf egdfcab cfegad
+acbdf gbae feadg eb egbdfc ebfgcad efbad deb fgdbea adgcef | ebd eb bcadf fbdac
+fde daegbfc fgabd deacfb egad gfceb gafbdc gbedf ed abegfd | bfadce cefbg fbgcad fabgd
+cbade eab becfad acfbdg dbgcaef gdaec gfadeb eb cafdb bcef | edbca fbcdaeg fcdgeab afcbd
+dacg gaf fbcdg bcgaf bdgeaf fcagbd fbeac ag gbcefd aebgcfd | cdbgf fga ebcfdag fgcadb
+bed db dcageb gbdf dfgceb cebfg fcdae cbefd gebfac afgdcbe | egbcdf begdcf dfgceba bd
+egcfd gbde defbagc cebafg dcg gd edcfa bdfecg fegbc gcdbfa | bcegaf cegdf fcabgd fdecg
+fb fbeg egdcaf cbf efgcd fagbedc ecdbf cbgefd cfadbg bcead | fdeacg faegbdc gbedcf bcf
+abefd bcgfeda bcage acbde ebacgf cd dcb ecdfbg dceabg dgca | gacd agcd dc debfa
+cdbgaef cfd cf dfega edfgab dfegac ebfdcg fdagc gbacd caef | cegdfa fc feadg afce
+afdgcbe gef bcafeg gfbad gecda ebdf ef gdefa bafedg fdbagc | fdbe ef egfcab dgbcaf
+cageb gfebcd adfg caegfd cfdbaeg bdcfea ead ad agced dgfec | gecab bedacf efgcd gfad
+bed bdfaec bgcedf bgadfec ed fgecb dcgeb dgcab gefd abcgfe | cegfb cgbdef gdef dacbfeg
+gfbce ge egf dfagbc degcaf efacb bcgfd afebdcg bdegcf gebd | egbd fadgce gbed gbcef
+bcgedf fgde dgebfac fg gfbdc dbcgea gfc decbg fcbad gcebfa | cbdgf fgbdc cbfdgea fgc
+baecfd dfge agecfbd bgdae bgafcd fgadb ed cgabe deb defbga | dfbag degf eadbg fged
+cbfadg gbec acebd cgfead bc beafd baedgc cbd cegad gefdacb | gacde dcfagb egdca aebcd
+agef dea edcbfg dcgba dcefg cedgfab ecgda ea bfeadc cfadge | ecbdgaf bcdeaf dbacg bedgcfa
+aegcb cbgfda gaedbc afcdebg ecdg ec facbde ceb efbga cgadb | cgbeadf cged egfdacb dfceab
+bedfc dfegbc gcbad cbeagf egdf fdgcaeb ge cgdbe geb abcefd | eg cabfge efbacd gebdcf
+dacef fegbadc bc cbfg dagbf dfgaeb afbgdc fcdab bgadce acb | cfbg gcbf afdec fdcae
+ebgaf be bge fgbda afbcdeg cgaef bcdagf fbaedg efbd agebdc | afdgcb efbd gbe adbgf
+agbdecf acgfeb cgbae fcae ae egfdba agbcd egbcdf ega gefcb | cfgeb cageb ea eag
+cbe fdgbe ebdfag cabdefg ec fbdce cegdfb gcef gcadeb cdbfa | acfgdeb gcfdbea cbefgd gfadbe
+gdcfeb bf bdf edgabc fgbc gbdce ecdbf gdeafb dfeac ceagdbf | fcgb gbdce fbedacg gfbdea
+bag gbfacd egafc afcbed cdbg gadfbe fdcba gb becagfd afbgc | cagfdb bga fgcea bdacegf
+gadbf cbaedgf dfeacb fg defba dfg fgeb gedbaf dagbc gecfad | degafb cefgda gdf dgafec
+dbfaec fg degab bgfcde ecfagd fgaed dfg cafed bgafced agcf | gdaefcb gcaf acebdf gf
+ebgfc eagdc eadf agbfcd gfa feacg cdegbaf dgbaec fa cfdega | edcagf gcdabef geacd fdae
+gabcdef fadg aedfb dcgbfe afbecd egd aedgb cbega afebdg dg | bafed dgaf gbeac deg
+fbgecad badfce eb befa efcda aedcb gfcedb edb bcgad afdecg | aefb facde cadgb bed
+fabcdg bfc adbf cgdaeb fdgec acgdfeb gbecaf gcfbd fb bdgca | fb acbgde cabdgf bf
+fdgcea ca bdfag cbdfgae acd bcdgea bdegc beca agdcb dgfbce | fdecag adc cad cdgeb
+gfcb abgef deafbcg aebdcg ebgcaf caefg gb fdceag gba afdbe | eagcfd bgcf adgcfe bcfg
+dfbcga ebdfac fcge bfcegd adbeg fg gfd beafdgc fdebg bfdce | gfacedb cbfagd ecfg afbced
+gfecabd dacefg bade aeg bfgea cebfg ae fdbga bagcdf eafdgb | adbe beda edab degbfa
+dbc cdbeaf gedbfa acdeg cb abcf edfba cfbegd aedcb defgacb | bc aecdg aefbcd egdca
+fcbed cdg agbcf bgedcf gd cbefad bgdcf gbed gefadc badgfec | bcfgd bged dcg fdebc
+fgdc egbfac eafdg gedac dgefbca ecdabg dbfae gdafec gaf fg | fdabe aedgf bdeaf gfdc
+dg cdafebg cfgaed gbda gcbead deg cfbeg cdeabf gebcd adbce | dg bcgde gabd gde
+cgb cbegd cg fecgab febcd gaedcb fadbeg gebad dgca efdbagc | cg bcg dgaecb ecdbga
+egfbda dbeca fd gcbaf bgafedc fbd efcd dgecab bfadc ecdfab | eagbfd dbcea edcbga cfed
+fceadgb beadf bdefca gfebcd bfca edafc fc cfd bgafde gcdae | acbf cf ebcdgfa daecf
+eacdgb gbdcfae gdfe cfbea gedcbf cfdagb bfd df gcebd fdecb | df bcfea dcabeg gfcedab
+ebgca bdfcge degbac dfbca gfbaecd eadg acgfbe de bde edcba | abgfced dbcgef adeg caegb
+acebfg bfdecga dea cafdg gfadbe bdeg bfcdae egbfa de fdeag | de dfcbgae fcadg fadcgeb
+aegcfb dbefg ebdc edfcg gfbeda agfcd cedbafg ce cfe decfbg | acbefg bgeadf dgefc faedbg
+eadgb bdcae bc acbg fgbecd gfdeab ceb cdafe agbecd gaebfcd | bcaged bc gbca bedca
+abfgc dbgeaf fc gdbfa dacf bgdfac gacbedf fcb egacb gdcbef | bcadfg cdaf fc bagce
+fbde gdafe de dbfeag bdceag fgace gafcbd fbadg cfdeagb gde | edfb eacbgd efgda deg
+cedaf ecfgbd dcg bdagef gbedf gc dcgbfa cgbe aecbdfg cfgde | cg cedfg cg dcg
+fbe bfgda ef dfgebca gbedfc bgcde daecbg efcg fgdbe fedcab | fbadg fbe bcaefd bef
+cega aefcb eabfg debfgca gfdba aefcgb bge fbcdge ge bdeafc | dafgb ebg fbcae fgeadcb
+fb dgaecf bdgec gacdf edacbf bfc cdgbfa bagf adgfecb cgbfd | fgba bf bgfcd cebdg
+facd cgbfd afdgbc agbfed af gaf acfbg becag cdgefb fgcaebd | gfbcad dafc dcfabg begfcd
+cfaged cdgfe efdca aedcbf fgca feg fg cdbge egbfad febgadc | gef cdefg becdg gfbead
+ecgdaf dbefcga bfg fbedga abcf cgfeb gbecd aecgf aebfcg fb | eacgfb cbaf caegfb gfb
+bec caed aefcb eacgdbf agbdcf ec faedcb cafbd aebfg bfcdge | fagdcb fbcad ecdgfab abegf
+gdecab cdaegf acgfb efbd bd edgabcf fgcdb gefdc gbd cebfdg | db cbgfa ebgcfd gcdebf
+fbced cdaefgb ae abgced dcgab dae cbgafd acefgd acedb geba | agdcb deagcb ae baeg
+adcef db ecgba gbfcde dabg fagbce bde cadebg cdabe gdbefca | edfca dcafe fdcegb dbga
+cabed ecagdf fcadgb cbagd bgde fecdbag de acefb gcdabe dec | gbdfac de begd cdeba
+dcegaf gc dbgfa dcbg dcgfab acbef edagbfc daegfb abcgf gac | gbcafed cg agdfb dcafbg
+eag gfdab fgecda bcgdef deca fdaeg efcgab gecdf ae cfgbade | eagfcb ae fagcde aecd
+aceb eadfcg gcadeb ea bgcda bagde dbfge badcfge gdbfac aed | ceabdg ead eda abec
+fcdg bgc bdcafeg abefdg gfcbad cgabd cdbea fcegab cg gafbd | efacbg gdcba dcaeb cgfabd
+gacbfe cedbga adecf ebcad abdcegf db cgaeb abdefg dcgb dab | bda ebcgfa acdbeg cedabfg
+dceabf acefgd cgfe dabgc dagfe dec egdca ce abcgdfe fegdab | gcfade gefc gacfbde degcfa
+aef gcbafe bgcfead gdaefc fgbe bceaf dbagcf abdce gcfba fe | gfeb ebgdacf efa fe
+cebafdg cagedb eg gecaf facbg daecf cge fdge bafcde efdcga | gdcaef bcgfa dfge efcda
+gfadc gbecf efagc cgdaeb gea cagedf ea fagdcb fgdacbe fead | bgcfdae ae daef gafec
+gcd cdea cgafbe dfgce dcgaef dc debgf edbgafc bgcdfa cegaf | cdg cdg acde caegfdb
+dbfgac gdabce fcdgb gbcefad adgecf edbcf bfag gbd gb afcdg | dbg agdcef ecfbd gfcaed
+bdcae fcabed gafdecb fbdeag bafed bceag cd fgaecd dec dcfb | dbfc fabedgc gfebda eacdb
+acgfd agcdbe bcfe gef afcgeb gdfeab ef gbedcaf beagc acgef | dcaegfb ef gdfceab efg
+fadegc egd gd egafcb afdeg fdeab agfec fgedbca dcebag cgfd | faegc agfce dcgefa dg
+fdgbeca bfecd becda gcdefa dagbfc edfbgc bfge fbd dfgec bf | fdbce fbcdag gbfe fbd
+afeg gfecda bfgdc dfecab af gdfac gdecab cdaefbg afc ecdag | fega bdcgf afc agedcf
+badec bgae fcade feadgbc becadg bfcagd be cabdg edb ecdfbg | gbea ecfad abdcg bcgfdea
+gfbea cabedg ed dabcegf eabfcg deb fabdc egfd abfde febgda | aefbd fgde degf fdeabg
+acdfeb fd gafcb egcfbad egadc gdfb caebgf fgadc fcgdab fad | fcgabd adf fd cfgba
+eabfcd bcadg aceg gabfed ag aecdb cdfbg dabecg gcebafd agb | cbade bga ag gcbdf
+fabgcd agefb cb dbefgc acefdbg fcgaed fabgc dbac dgafc cfb | bcgdfa fdbacge edgfca afedcgb
+dbaeg efcg beagfc fg bfgae gfabcde bdefac dgcabf bgf ceafb | eafcb aegfb fg fbg
+bdfeg af fcabged ecadg gbcaed fcadgb dgcfae faged dfa caef | deagc dfa gdafe fda
+df acgbfe bcfdg bcgdaef edfg gbdac dbaecf cdf ebgfc ebdgcf | gfcdb cdf fegcb eagdbfc
+daefb afcdg dbgecfa bgca dcbegf feadgc gb gfbcad gdbfa bgd | dgb gb fbeda gadcfb
+efacg febdc dfgbce acdbge acebgfd bfdg dg cdegf dgc aedbfc | bgdf gafec dg dcg
+fdgbe cbg gdfbc efgdba cbed bc bgafce cgafd bgcfdea gfedcb | bc gfcdb edbgf dfbgc
+bgdce bfgae efbcgd deafcbg cdegaf ebgfd gecbad dbfc gfd fd | df df agfcde ebcdg
+gcbda debga be gedcfab fbedga efbd fgaed bea gfaebc afgdec | aefdg adefgc acefgd abe
+egbdfc fbac bc dcage bfeagdc ebafd baedfg dbcae faedbc cbd | adcfeb fgdceb fdcgeb bacf
+ebfgd facedg begaf afbegcd def df dfgceb edgcab dbcf cbedg | fdcb fed dfcb bfceagd
+dbgec ebad gbcdfe ceadgbf ceadfg gacbf bcdage adg cadbg ad | cgbde cbgde gcbfa gabcf
+aebgdf fabeg da bgad cbfde bcagef cafbgde edfab fecgad ade | fdabe gafdbe edfab dea
+bda ad bgaef ecbfag cdefb faedb badgef gabecd dagf cbeagdf | bad fdgbcae egbafd gdeabf
+gf eabgd begfca bcgdae aebcgfd gaf gfed fbadg cbdfa dbeafg | fbcda fdabg acfbd fdeg
+agdbce dcbfg gcefda acg ebdca defacgb fedabc egab ga gcbad | bega abge gac fceadb
+ebfcdg afcbed bad dafge ba gacfbd gcebdaf dgabf abgc cbdfg | acbg bfgdec cgebdfa gfcbd
+gabedf adfe bacgfe fgadb adbgecf fa gdaeb fdcbg gcdaeb afg | acegfb fa gaebd gaf
+fegca afg gebfdca fa daef cabdge dceag dcfgae acbdfg efbgc | aefgbcd gebdca fga afdgbc
+dagfe cfabgd dgefc gacedfb ga baegdf gfa bdafe egba fbedac | fbdagc egba cgdef gfa
+bfadce fdagbe fgbde cgdfbe da ebcga badeg dbcfage fagd ead | fgdaecb dabgefc adgf ade
+adbecg ab abe cdgeb dafec cgbdafe badce gcfeab cgbedf dbga | dgaefbc adbg abdgecf dabcfge
+ebd abdec gbdafe bdgc bd ebfca gcdea gadceb cfabedg fcegda | bdcae bd aegdfc eadgcfb
+ce cge bgfeacd fcbge cgdbfe aefbg dgacfb fced badegc bcdfg | gfabe dagcbe adfebgc cdaebfg
+gecadb fb gbf gdbfeac acfgb eafcg bgadfe gdbac fcdb fcbgda | fdbc cdaefbg bf edcbag
+ce cde bcdfgae abdfe fcagd bdgcae dagbfc dgafec egfc dfeca | cbadge bgfdeca dfeagc ecd
+abcegd dagfc fgbdc fadecg agbf dcgfab fgdacbe bdg bg fbdce | bfcgaed ecdbag fabg dagecf
+dafbe edgabf dcb cb fegcd becfda cbagfd aecb acdgbfe ebfcd | efabd aceb bdc dgbceaf
+edgbcf bfacd efgb dabcge cdgef bg facdge fbcdg bagcdfe gcb | cefadg bgc cbdgfe bcg
+dfbce baec gfbecda fbegdc cefadg edbcfa ea gdfba ead aebfd | aecb ea aceb ead
+bfcaeg fag af egdcba egbdacf cbfa gfabde gceab ecgdf aecfg | bcega bcaf ecdfg dfbcage
+ebadcgf eaf gdfbe baegdc fgac dgeaf af dgfcea acdebf aedcg | fdecga edfga efadg cdegfa
+decagfb bdgfac efcba gfcdbe dbacf bec cdae ec becafd begaf | cefab bdecaf bcfdae cefgdb
+eagdcbf abfde abcde daf dcbafe geabcd bgdfe fa gafecd cfba | af eagbcd ecdba defbg
+cgfdab fdbe bdfcg cgfde de gaedbc egdbcf cedgbfa cfaeg deg | ecgdfb ged bedf bdcfg
+afbgc egafd gdb gbfdea afdgb db edafgc dgcfeba debfcg abed | gdb cfgbde db db
+degcbaf acfd fc gfbac dfcgbe eagbc degbaf dabfg fgc cabgfd | gdfbcea acdf eabgfd egacb
+decaf eadcbf fcbgd ab facdb aecgbd efgacd cfadgbe abd feab | bdeagc cadfe beaf dcagbe
+faecb adecf fbeagc gbec cbf cbadfeg bc bcfdag geafb fbdega | cgbe eacgfb edcfa cfb
+bacdgf cfabe cdaegbf bacfeg cgdbae bf bcf ecfda bfeg aebcg | gebf bf cdfae cefad
+bdgcfa bgcfd eb cgaefb adceg bfde ceb cbfedg agfbecd dcegb | dbfe fcdagb cgfeba bce
+edfabg badge egbdf gbcdea fde befgacd fe aefb dbfcg cgadfe | gefbd gdbfe edf fbdeg
+eaf gdecaf febacg egacb ef dcfab bgfe cgebad egafcbd cbeaf | fae fbacd cgabe agfcbed
+ed egdf edafb efcab fgbdae eda cfagbd cabgefd debacg bdagf | eda ade fgde dgef
+fcade be bgafc cedbafg caefgb bea dfbgea bfcae cbeg dbacgf | aecfb aeb ebcaf beafc
+cfg bgdfeac bcdfe abfgd fdgbc adgfcb cg acdg gfceba fbeagd | bafdg cdebf acgbfe ceadgbf
+gbecadf cadgbf dgefba bgcfe ga abg afbgc dcafeb dgac adcbf | bfgdac agcd bga agb
+befdga ce gbafc baecdgf egc bedgac gfdecb bgead gcbea caed | ecg daebg ce aebcgd
+edcag eacdf dfcba fe dcfgea degcab bacfeg cfe gefd agfbdec | gfecba ef fdeg edgf
+ceafd cafbge df afd cdbea dfagce bgcedfa bdfaeg gface fcgd | feagbc cdgf cdfg ceafg
+cfebg gcbdae bdaefgc ea gabdc eag fcabdg cdea abgec fegdba | bdcagf ceda feadgb ea
+bacfe dbafe gbedac bfaged df fdb fadg edcgbf adbeg gecfdba | fgabde gdcabef efagdb egfcbad
+cbafedg dcefa adgcb gabe degac gfbcad acedgb ecfdbg egc ge | gcfadb dabefgc aegb eg
+bdaec gdeca dbc ecdbgf fbeagdc fbeadc afebc db gfbcae afbd | gbfecd gcebdfa fedacb gebcdf
+cdgba agfcb cgfebd fb fcega gbecad cbf decafbg cdfagb fabd | fb gcdba badgfc cgbafd
+agdeb adgec edcgba cegabfd cdfaeg afbgd dbe eb ebcg dabfce | cadgfe eb gdcbea deacg
+gbdaf fgebda bda fgaecd fdgea dcbeaf bgea ab befcadg gdcbf | gedbafc ab cbdgf adb
+bdfga fdcbeg bgcefa deafcb begdf fcbed agdbefc ge gced bge | fcbaeg ge fdceb ebg
+agecf fedcbag fd ecbgd afcdeb fceabg gdfa daegfc cdgfe dfe | agfd gfecd dgcfe gfecd
+bcfa egdbf eagcdf dbfec acfdgeb cdfea becfda bcd acedgb cb | cbd bdc edabcg bdefac
+cgbf aegdc gdfeabc acfbed fec debgf fagbed dfecg fc febgdc | abcfed febdg cf bfecad
+dfcbe dbcfgea cgaef gecfab bae bcga ba ceafb gefacd debafg | acbef fdcbe ab eba
+aecfb becgdf cf fcag bdaec agcfbe agbef debafg cefbadg fce | cef cfe aecbd efc
+fcgbad ebg fged eg gabef cbafe gbeadf fgdceba abdegc dbgaf | dabecg gedf gdaebfc bfeagd
+fegbca cegbf cag bcafg ga gadbefc fdcega edbgfc fcdab geab | ag dbafegc ga acbfg
+abcd dgacf fcedgb bfd db cfdbaeg agbfe fbcadg bfadg ecgadf | fdb dgecfba bfgda bcad
+fbgde efbda bea adbfeg acdgefb eafg fecgbd ebdgac ea abcfd | abfde fbcagde edfgb abe
+dafgbc adgec cbaegd bgdafec bgeac gbed dg edacf dag eagbfc | debg fbedgca edgb gda
+eb abce bafge fgdbce ceabfdg agcbf fbcage cfgabd ebf gadef | fadeg cdegbf fcabdg gcbfea
+gc dbcae aebgfc cbg gbeaf ecfg egfdab afebgcd cafgdb aegcb | fcge cbg fegc gfbea
+fbegda bfd bfdace gceabd cfbga edgf bedfacg debga bgfad fd | bgfade acbdfe feabcd eabdgc
+eadfbg ge cdaegbf bfgdc gcadbf ecfbg ecfab fbcdge egcd fge | fbace ceafb faceb degabf
+gdba cbagfde gb fecdg gedbfa acbgfe dfgbe bafdce gbf adefb | dbefa dfbae decgf bedgf
+fbe agfce ebadcf fbcdga fedagbc gfcdb egbfcd fbegc bged be | egafc gebd bgafcd edbg
+bfcge efacg ae fdgac cea cbfdae bfgadc gfdcae gdae adfecgb | efdcab gface fcgbda gfebc
+eagfc dacbfg cgefb cdfgea ebgafcd acde ae fae cgafd aefbgd | egcfa agcdf befgc gbacdf
+gfecab gfdbac efcgdba cfabd gac dcbag ag cdebg dafebc fgda | gacebf adcbf bcgde cag
+gbfcd cadeg cfbgde cfab adf af edbgaf dfgbca adgcf aefdbgc | adf afd fda fdacgb
+cbg defgbc geafb bcda gdefcab cagfd cfaedg gfbac bc bdgfca | fcgba fbdcge cb gafeb
+ca ebcgdf gadbec cda aedfb gfdbc baecfdg bacdf cfag adcgbf | cfga efabd ca badfc
+cgabdf da fdca cebag bcdag cabdfeg fbgcd dab bedfag fdbecg | dba cdaf gbdfce eacgb
+cbgf becfag cegad febadc afc gfcae becdfga adbefg cf gefab | afbdgec aegbf eagbf acf
+bg edgfa dgcb dgbcfa fbagd dabcf edfcgab agb efacbd ebafcg | acdfb fdcab fdcba gb
+de cged feadg fabedc cafgd fbage dfe edcbgfa agbdfc dgafce | gcde gfeab gafcd gabfe
+abec fgbcdae gfcab ebfag cgaedf ae ceabfg eaf gabfcd gfbed | gfbaced bgfca ae gdbfe
+fcdgba cagdfe cfbeagd bcfg afbdg cga cg gbadfe badgc cdbae | fdgeab cg dfgace gdabf
+gfbdac dcfeag edfgcb dbc cb bdagc cbaf cdfag aebgfdc bdeag | gafdc bcd gdcaef bc

src/bin/08.rs

@@ -0,0 +1,118 @@
+fn main() {
+    println!("First solution: {}", part1());
+    println!("Second solution: {}", part2());
+}
+
+fn part1() -> usize {
+    input()
+        .iter()
+        .flat_map(|p| &p.challenge)
+        .filter(|s| matches!(s.count_ones(), 2 | 4 | 3 | 7))
+        .count()
+}
+
+fn part2() -> usize {
+    input().iter().map(Puzzle::solve).sum()
+}
+
+type Digit = u8;
+
+/// Parse chars a to g to bit flags.
+fn parse_char(s: char) -> Digit {
+    match s {
+        'a' => 1,
+        'b' => 2,
+        'c' => 4,
+        'd' => 8,
+        'e' => 16,
+        'f' => 32,
+        'g' => 64,
+        err => panic!("invalid digit '{}'", err),
+    }
+}
+
+fn parse_digit(s: &str) -> Digit {
+    s.chars().fold(0, |a, b| a | parse_char(b))
+}
+
+#[derive(Debug)]
+struct Puzzle {
+    hints: Vec<Digit>,
+    challenge: Vec<Digit>,
+}
+
+impl Puzzle {
+    fn solve(&self) -> usize {
+        // Easy numbers have unique numbers of segments
+        let one = assert_single(self.by_segments(2));
+        let four = assert_single(self.by_segments(4));
+        let seven = assert_single(self.by_segments(3));
+        let eight = assert_single(self.by_segments(7));
+
+        // Only three overlaps one
+        let three = self.by_segments(5).find(|&n| n & one == one).unwrap();
+
+        // Only nine overlaps four and seven
+        let nine = assert_single(
+            self.by_segments(6)
+                .filter(|&n| n & four == four && n & seven == seven),
+        );
+
+        // Find zero. It has 6 segments, is not nine and overlaps one.
+        let zero = assert_single(self.by_segments(6).filter(|&n| n != nine && n & one == one));
+
+        // six is the only 6 segment number that's not nine or zero
+        let six = assert_single(self.by_segments(6).filter(|&n| n != nine && n != zero));
+
+        // To get five, join one and six. That is a single segment that only five and three have, but we know three.
+        let five = assert_single(
+            self.by_segments(5)
+                .filter(|&n| n & one & six > 0 && n != three),
+        );
+
+        // Only two remains
+        let two = assert_single(self.by_segments(5).filter(|&n| n != five && n != three));
+
+        let nums = [zero, one, two, three, four, five, six, seven, eight, nine];
+
+        // We can now decode the challenge
+        let mut result = 0;
+        for &d in &self.challenge {
+            result *= 10;
+            for (i, &n) in nums.iter().enumerate() {
+                if n == d {
+                    result += i;
+                }
+            }
+        }
+        result
+    }
+
+    fn by_segments(&self, n: u32) -> impl Iterator<Item = Digit> {
+        self.hints
+            .clone()
+            .into_iter()
+            .filter(move |d| d.count_ones() == n)
+    }
+
+    fn from_str(s: &str) -> Self {
+        let (digits, test) = s.split_once('|').unwrap();
+        Self {
+            hints: digits.split_ascii_whitespace().map(parse_digit).collect(),
+            challenge: test.split_ascii_whitespace().map(parse_digit).collect(),
+        }
+    }
+}
+
+fn assert_single(mut it: impl Iterator<Item = Digit>) -> Digit {
+    let result = it.next().unwrap();
+    assert_eq!(it.next(), None);
+    result
+}
+
+fn input() -> Vec<Puzzle> {
+    include_str!("../../input/08.txt")
+        .lines()
+        .map(Puzzle::from_str)
+        .collect()
+}