Ƙera tsarin na musamman yana nufin hadaddawa da tsarinai da akwai kaita yadda kowane aiki da aka buƙata ya bugi abin da ake son gabatarwa, na bari tsari ɗaya ya rufe laifi na wanda. Wata fasahar gida ita ce haɗa hash map tare da array, heap, ko jerin shugabanci.
Buƙatun: , da kowannensu a cikin O(1). Hash map ɗaya ba zai iya O(1) random ba; array ɗaya ba zai iya O(1) remove ba. .
insert(x)remove(x)getRandom()import random
class RandomizedSet:
def __init__(self):
self.idx = {} # value -> index in list
self.vals = [] # values for O(1) random pick
def insert(self, x): # O(1)
if x in self.idx: return False
self.idx[x] = len(self.vals)
self.vals.append(x)
return True
def remove(self, x): # O(1): swap with last, pop
if x not in self.idx: return False
i, last = self.idx[x], self.vals[-1]
self.vals[i] = last # move last into the hole
self.idx[last] = i
self.vals.pop()
del self.idx[x]
return True
def getRandom(self): # O(1)
return random.choice(self.vals)
1. List every required operation + its target complexity.
2. For each, name a structure that hits it:
by key O(1) -> hash map
by index O(1) -> array
min/max O(log n) -> heap
ordered O(log n) -> balanced tree / skip list
O(1) splice -> doubly linked list
3. COMBINE them; use the hash map to map keys -> positions/nodes
in the other structure so updates stay O(1).
4. Verify each operation against its target.
| Tsauri | Tsarinai haɗa | Abin da yake ba |
|---|---|---|
| LRU cache | hash map + doubly linked list | O(1) get/put |
| O(1) randomized set | hash map + array | O(1) insert/remove/random |
| Min in O(1) on a stack | stack + auxiliary min-stack | O(1) getMin |
Sistemin gaske ba kadan suke buƙatar tsari ɗaya na littafi — suna buƙatar haɗare mai amfani ga tsari na samun ƙarami, wanda jiya ke bayarwa ne.
Masu tambayar buƙata suna amfani da waɗannan matsaloli don gwada ko za ka iya yunku daga tsada aiki zuwa haɗawa, fasahar da ta dace na bayan ƙera system mai aiki sosai.