Amanani aphambili ukubamba indawo ebalulekileyo kwimathematika nakwicomputing. Ngokusisiseko, inani eliphambili linani eli-natural elikhulu kunelinye kwaye alinazahluli ezi-positive ngaphandle kwesinye kunye nayo ngokwayo. Umzekelo, amanani amathandathu okuqala ngu-2, 3, 5, 7, 11, kunye no-13. Ukuqonda kunye nokusebenza ngamanani aphambili kubalulekile kwiindawo ezininzi, ezinje nge-encryption algorithms kunye nefactoring, phakathi kwezinye.
Isisombululo kwiNgxaki yeNani eliyiNkulumbuso
Umba ophambili onamanani aphambili kwiprogramu okanye kwimathematika yokubala kukuqinisekisa ukuba inani elinikiweyo liphambili okanye hayi. Ukuchaneka, injongo yethu apha kukuvavanya ukuba 'n' (non-negative integer) linani eliphambili. Ukusombulula le ngxaki, siya kuphumeza i-algorithm elula.
Indlela yethu izakuquka ukujonga ukuba 'n' akaphindi nakuphi na inani elipheleleyo phakathi kuka-2 kunye nengcambu ka 'n.' Ukuba akunjalo, sigqiba ngelithi 'n' linani eliphambili. Oku kusekwe kwinyaniso yezibalo yokuba umba omkhulu yenani usoloko uphinda-phinda into encinci esele ijongiwe.
Ikhowudi yeCobol yokumisela iiNombolo eziNkulu
Eli candelo libandakanya ikhowudi efunekayo ukusombulula ingxaki yenombolo yokuqala kwi-Cobol. Nantsi indlela yokwenza:
ICANDELO LOKUCHAZA.
INKQUBO-ID. Engundoqo.
ICANDELO LEDATHA.
UKUSEBENZA-UKUGCINA ICANDELO.
01 Num PIC 99.
01 x PIC 99.
UKWAHLULWA KWENKQUBO.
QALA.
UBONISA “Faka inombolo : “.
YAMKELA iNum.
YENZA NGOKUGUQUKA x UKUSUKA ku-2 NGO-1 UKUDE KUYE ku-x * x > Num
UKUBA iNum MOD x = 0
BONISA iNum ” ayilonani eliphambili.”
PHUMA INKQUBO
ISIPHELO-IF
PHELA-UKWENZA.
BONISA iNum ” linani eliphambili.”
MISA UKUBALEKA.
Qonda iKhowudi
Alandelayo ngamanyathelo esisombululo senani lokuqala:
- Siqala ngokuchaza iinguqu ezimbini, 'Num' kunye 'x'.
- Sicela inombolo kumsebenzisi kwaye siyigcine ku-'Num'.
- Okulandelayo, usebenzisa i-PERFORM loop, siqala ukwahlula 'Num' ukusuka ku-2 ngokunyuka. Siqhuba oku de 'x' ophindwe kabini mkhulu kuno-'Num'.
- Ngaphakathi kwiluphu, ukuba 'Num' inokwahlulwa ngokulinganayo ngo-'x' (okt intsalela =0), 'Num' ayilo nani kwaye siyayiphelisa inkqubo.
- Ukuba siphuma kwiluphu ngaphandle kokufumana 'x' onjalo, ngoko u-'Num' linani eliphambili.
Amathala eencwadi kunye neMisebenzi eBandakanyiweyo
Le nkqubo yeCobol elula ayifuni naziphi na iilayibrari ezongezelelweyo okanye imisebenzi. Kukho ukusetyenziswa kwesiseko se-syntax yolwimi lwe-Cobol, kwaye sixhasa imisebenzi ethile eyakhelwe-ngaphakathi efana ne-ACCEPT (ukufumana igalelo lomsebenzisi), i-DISPLAY (ukuprinta kwikhonsoli), kunye ne-PERFORM (ukudibanisa ngaphaya kwezahlulo ezinokubakho). Umsebenzi weMOD usivumela ukuba sifumane intsalela yolwahlulo, nto leyo engundoqo ekusombululeni ingxaki yenani eliphambili.
Nokuba wenza izitshixo ezikhuselekileyo zoguqulelo oluntsonkothileyo okanye ufuna amanani aphambili kweminye imisebenzi yokubala, ukuqonda kunye nokukwazi ukumisela amanani aphambili sisakhono esibalulekileyo kuluhlu lwakho lwenkqubo. Ziqhelanise nesi script seCobol ukuze uqaphele kwaye usebenzise amanani aphambili ngokufanelekileyo.
