La classe Queue utilizza una lista
class Queue: def __init__(self): self._lista=[] def enqueue(self, x): self._lista.insert(0, x) def dequeue(self): return self._lista.pop() def is_empty(self): return (len(self._lista) == 0)
Test 1
coda=Queue() # [] coda.enqueue(18) # [18] coda.enqueue(1) # [1, 18] coda.enqueue(28) # [28, 1, 18] print(coda.is_empty()) # False print(coda.dequeue()) # [28, 1] 18 print(coda.is_empty()) # False print(coda.dequeue()) # [28] 1 print(coda.is_empty()) # False print(coda.dequeue()) # [] 28 print(coda.is_empty()) # True
Test 2
coda=Queue() # [] for x in range(5): coda.enqueue(x) print(coda._lista) # [4, 3, 2, 1, 0] while(not coda.is_empty()): print(coda.dequeue(), end=" ") # 0 1 2 3 4 print() print(coda._lista) # []
Continua…
Aggiungi i metodi
- x <– top(), il primo elemento inserito?
- x <– bottom(), l’ultimo elemento inserito?
- n <– size(), quanti elementi contiene la coda?
- …