Isinyathelo 15 · Okochwepheshe
XY-Wing: liyini leli qhinga? Indlela yokuxazulula i-Killer Sudoku
Izikwele ezintathu, ngasinye sinezinombolo ezingenzeka ezimbili — esiphakathi u-XY nezimbili ezisibonayo, u-XZ no-YZ — zikuvumela ukuthi ususe u-Z kunoma yisiphi isikwele esibona zombili lezo zikwele ezimbili.
Liyini leli qhinga
Yakhiwe ngezikwele ezintathu, ngasinye sinezinombolo ezingenzeka ezimbili.
• Isikwele esiphakathi (pivot): 1 noma 2
• Isikwele A (sibona esiphakathi): 1 noma 3
• Isikwele B (sibona esiphakathi): 2 noma 3
Uma esiphakathi singu-1, u-A ungu-3. Uma esiphakathi singu-2, u-B ungu-3. Ngakho u-A noma u-B uhlala engu-3.
Lokho kusho ukuthi noma yisiphi isikwele esibona kokubili u-A no-B angeke sibe ngu-3.
Ungalibona kanjani
Qala esikweleni esinezinombolo ezingenzeka ezimbili, bese ufuna ezinye izikwele ezimbili ezinezinombolo ezimbili esizibonayo. Izikwele ezintathu, izinombolo ezintathu, ipheya ngalinye lihlanganyela inombolo eyodwa.
Isibonelo
Izindawo ezizungezwe ulayini wamachashazi yizibaya, isamba sisekhoneni eliphezulu kwesokunxele. Izikwele eziphuzi zikhombisa ukuthi ubheke kuphi, ezisawolintshi ziyisizathu, izinombolo ezibomvu yizinombolo ezingenzeka ongazisusa, kanti inombolo eluhlaza okotshani iyimpendulo.
Isikwele M4K8 singaba ngu-6 noma ngu-7 kuphela. Uma singu-6, isikwele M6K7 siba ngu-4. Uma singu-7, isikwele M2K8 siba ngu-4. Ngakho esinye sezikwele M6K7 no-M2K8 sihlala singu-4, futhi noma yisiphi isikwele esibona zombili (M2K7, M5K8 no-M6K8) angeke sibe ngu-4.