Multimap C++ yog dab tsi?

2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47

Multimaps yog cov ntim khoom sib koom ua ke uas cov khoom lag luam tsim los ntawm kev sib xyaw ntawm tus nqi tseem ceeb thiab tus nqi mapped, ua raws li kev txiav txim tshwj xeeb, thiab qhov twg ntau lub ntsiab tuaj yeem muaj cov yuam sij sib npaug.

Yog li ntawd, Multimap yog dab tsi hauv C ++?

Ntau daim ntawv qhia hauv C ++ yog associative container likemap. Nws sab hauv khaws cov khoom hauv tus nqi tseem ceeb. Tab sis tsis zoo li mapwh uas khaws cov yuam sij tshwj xeeb, ntau daim ntawv qhia tuaj yeem muaj duplicatekeys. Tsis tas li ntawd, nws sab hauv khaws cov khoom hauv kev txheeb xyuas ntawm cov yuam sij.

Tom qab ntawd, lo lus nug yog, qhov txawv ntawm MAP thiab Multimap hauv C ++ yog dab tsi? Cov daim ntawv qhia thiab cov ntau daim ntawv qhia yog ob qho tib si ntim khoom uas tswj cov khoom tseem ceeb / nqi raws li ib qho khoom. Qhov tseem ceeb qhov sib txawv ntawm ob yog qhov ntawd hauv ib daim ntawv qhia cov yuam sij yuav tsum yog qhov tshwj xeeb, thaum a ntau daim ntawv qhia tso cai duplicatekeys.

Dhau li ntawd, yog Multimap txheeb C ++?

ntau daim ntawv qhia ::emplace() hauv C++ STL-Inserts tus yuam sij thiab nws cov khoom nyob rau hauv lub ntau daim ntawv qhia thawv. ntau daim ntawv qhia ::begin() thiab ntau daim ntawv qhia ::end() hauv C++ STL– pib() rov qab ib tug iterator xa mus rau lub firstelement nyob rau hauv lub ntau daim ntawv qhia thawv. ntau daim ntawv qhia ::erase() hauv C++ STL- Tshem tawm tus nqi tseem ceeb ntawm qhov ntau daim ntawv qhia.

Puas yog Unordered_map sai dua daim ntawv qhia?

The std:: daim ntawv qhia xav tias feem ntau yuav qeeb dua tshaj tsis tau txiav txim daim ntawv qhia tab sis yeej muaj lawv siv ifordered nkag yog tsim nyog. The std:: unordered_map muab khaws cia rau hauv lub rooj hash. Qhov no tso cai rau sai dua nkag mus rau cov ntsiab lus raws li kev suav hash ua tiav ntawm keyvalue.