Izinhlelo Dynamic, izimiso eziyisisekelo

Ukuze ukhethe isixazululo elilungile lapho enza imisebenzi izinhlelo ngezinye izikhathi kudingeka ukuhlunga esiningi idatha inhlanganisela ilayisha inkumbulo ye-computer siqu. izindlela ezinjalo zihlanganisa, isibonelo, indlela izinhlelo "uhlukanise futhi umthetho". Kulokhu algorithm inikeza inkinga ngokuhlukana ku subtasks ahlukene ezincane. Le ndlela isebenza kuphela lokhu ikakhulukazi ezimweni lapho subtasks ezincane Okusizayo ezimele. Ukuze ugweme umsebenzi ezingadingekile uma kuncikene sub-imisebenzi, isebenzisa ashukumisayo izinhlelo indlela ehlongozwayo American R.Bellmanom in the 50s.

indlela

izinhlelo Dynamic kutfola ikhambi elilungile inkinga n-ntathu, ukwabelana n izigaba yakhe ehlukile. Ngamunye wabo a sub-umsebenzi ngenhlonipho komunye onhlobonhlobo.

Inzuzo enkulu le ndlela kungenziwa kubhekwe ukuthi onjiniyela ehilelekile inkinga eyodwa-ntathu nokwenza subtasks esikhundleni inkinga n-ntathu, futhi umgomo wethu oyinhloko uya "phansi-up".

Kungcono ukusebenzisa izinhlelo ashukumisayo lokhu ikakhulukazi ezimweni lapho sub-imisebenzi zihlobe-, okusho ukwabelana amamojuli ezivamile. I-algorithm inikeza isinqumo ngayinye subtasks kanye, ukulondoloza izimpendulo wenziwa itafula ekhethekile. Lokhu kwenza kube nokwenzeka ukuba abale impendulo lapho ephinde ehlangana ne okufanayo sub-msebenzi.

Dynamic izinhlelo umsebenzi uyayixazulula inkinga nokwenza. Umbhali le ndlela iye owasungulwa R. Bellman optimality Isimiso: kungakhathaliseki ukuthi isimo sokuqala ngamunye izinyathelo kanye nekhambi kuchaziwe lesi sinyathelo, konke okulandelayo ukukhetha elilungile maqondana isimo, okuyinto uthola uhlelo ekupheleni isinyathelo.

Indlela ngcono ukusebenza imisebenzi ixazululwe esebenzisa ezahlukeneyo, noma recursion.

Isakhiwo umsebenzi algorithm

Dynamic izinhlelo algorithm kuhilela ukwakhiwa imisebenzi yokuthi umsebenzi ngakho ihlukaniselwe subtasks emibili noma ngaphezulu ukuze isixazululo yayo yakhiwa isixazululo elilungile bonke subtasks, sifaka. Ngaphezu kwalokho, kubalulekile ukuba ubhale maqondana Ukuphinda, futhi kubalwa elikhulu wepharamitha umsebenzi lilonke.

Ngezinye izikhathi, esinyathelweni 3rd iwukuba ngekhanda ezinye sendlalelolwati ezengeziwe ngentuthuko somsebenzi ngamunye. Lokhu kubizwa ngokuthi i-stroke ukubuya.

indlela Isicelo

izinhlelo Dynamic kuyasetshenziswa uma kukhona izici ezimbili isici:

• eliphezulu subtasks;
• khona kule nkinga of agqagqene subproblems.

Ukuxazulula le nkinga nokwenza ngokubeka izinhlelo ashukumisayo, okokuqala udinga ukuchaza isakhiwo yesixazululo. Umsebenzi kufanele kube elilungile noma ikhambi yakhiwa izinqumo ezingcono kakhulu subtasks yayo. Kulokhu, kungcono ukusebenzisa izinhlelo ashukumisayo.

Eyesibili impahla inkinga, kubalulekile kule ndlela, - inombolo encane sub-imisebenzi. isixazululo Recursive yenkinga usebenzisa okufanayo ezedlulayo sub-izinkinga, inani okuyinto incike ubukhulu Imininingwane kokuqala. Impendulo lilondolozwe etafuleni ekhethekile, uhlelo konga isikhathi ngokusebenzisa le datha.

kuphumelela kakhulu ukusetshenziswa izinhlelo ashukumisayo lapho ngokuyinhloko kudingeka umsebenzi ukwenza izinqumo ngezigaba. Ngokwesibonelo, cabangela isibonelo esilula senkinga esikhundleni kanye nokulungiswa imishini. Ake sithi ku ifektri umshini asakazwe ukwenziwa amathayi ngesikhathi esifanayo senze isondo amafomu ezimbili ezihlukene. Esimweni lapho elilodwa lamafomu ehluleka, kubalulekile ukuqaqa umshini. Kuyaqondakala ukuthi ngezinye izikhathi inzuzo engaphezulu esikhundleni futhi ifomu lesibili ukuze ukuqaqa umshini uma futhi leli fomu kuyoba lingaphumeleli esigabeni esilandelayo. Ikakhulukazi kusukela kulula esikhundleni kokubili ukuma ukusebenza ngaphambi kokuba uqale behluleka. Dynamic izinhlelo indlela inquma isu umhlabeleli endabeni esikhundleni salezi izinhlobo, ikhumbula zonke izici: izinzuzo amafomu Ngokuqhubeka yokuxhaphaza, ukulahlekelwa umshini Ukuphumula, izindleko amathayi kulahliwe nokuningi.