Menene skip list kuma ta ga aiki na O(log n) neman?

Question

IT Interview Practice · Accepted Answer

A **skip list** jerin layi da aka tsara ne wanda aka kara da maraka **"hanyoyi masu sauri"**. Manyan matakan suna runtsuwa akan noddin da yawa, don haka bincike yana sauko kuma yana gida a dama, yana samun rarraba O(log n) **rarraba - zaifin rabon tare da kanshi ita ce kawai mafi gida ga jiya mai daidai katako. ## Structure ```text L3: head ------------------------> 30 -------> NIL L2: head ----------> 17 ---------> 30 -------> NIL L1: head ----> 9 --> 17 --> 25 --> 30 --> 42 -> NIL L0: head -> 3->9->12->17->25->30->39->42 ----> NIL (full list) ``` Kowanne noda ana ƙawarewa zuwa manyan mataki tare da nasarar `p` (galibi 0.5), don haka a matsakaici kowane mataki yana da nodu guda biyu sauri fiye da wanda ake gida. ## Bincike ```text search(25): start top-left, move RIGHT while next <= target, else drop DOWN a level. Repeat to level 0. ``` ```python import random def random_level(p=0.5, max_level=16): lvl = 1 while random.random() < p and lvl < max_level: lvl += 1 # coin flips decide a node's height return lvl ``` ## Kyamada | Aiki | Jatantaci | Sarari | |---|---|---| | search | O(log n) | O(n) | | insert / delete | O(log n) | — | ## Sarrafi da gida katako - **Karfin:** gida a kai sauki fiye da red-black/AVL; babu juyawa; sauƙi jiya mabugaje (ana amfani a cikin Redis waje, Java `ConcurrentSkipListMap`). - **Laushi:** shawarwari (ba mafi muni ba); jitoci ƙari yawun nodda. ## Yawa Makilici Skip lists suna ba aiki mai ugur kamar katako a cikin O(log n) tare da code gada da sauƙi tsarain jiya ba tare da katon, wanda ke matsaya ga dai misali na Redis ya zaba. Su ne misali kyau na amfani da **randomization** don maye gurbin mahimmin digon. Ja ma'aikaci kakomu sauri gane ce.

Structure

Bincike

Kyamada

Sarrafi da gida katako

Yawa Makilici

Tambayoyi masu alaƙa