mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-28 05:16:28 +08:00
1c0f350ad6
* Add the intial translation of code of all the languages * test * revert * Remove * Add Python and Java code for EN version
98 lines
2.8 KiB
Python
98 lines
2.8 KiB
Python
"""
|
|
File: array_queue.py
|
|
Created Time: 2022-12-01
|
|
Author: Peng Chen (pengchzn@gmail.com)
|
|
"""
|
|
|
|
|
|
class ArrayQueue:
|
|
"""Queue class based on circular array"""
|
|
|
|
def __init__(self, size: int):
|
|
"""Constructor"""
|
|
self._nums: list[int] = [0] * size # Array for storing queue elements
|
|
self._front: int = 0 # Front pointer, pointing to the front element
|
|
self._size: int = 0 # Queue length
|
|
|
|
def capacity(self) -> int:
|
|
"""Get the capacity of the queue"""
|
|
return len(self._nums)
|
|
|
|
def size(self) -> int:
|
|
"""Get the length of the queue"""
|
|
return self._size
|
|
|
|
def is_empty(self) -> bool:
|
|
"""Determine if the queue is empty"""
|
|
return self._size == 0
|
|
|
|
def push(self, num: int):
|
|
"""Enqueue"""
|
|
if self._size == self.capacity():
|
|
raise IndexError("Queue is full")
|
|
# Calculate rear pointer, pointing to rear index + 1
|
|
# Use modulo operation to wrap the rear pointer from the end of the array back to the start
|
|
rear: int = (self._front + self._size) % self.capacity()
|
|
# Add num to the rear
|
|
self._nums[rear] = num
|
|
self._size += 1
|
|
|
|
def pop(self) -> int:
|
|
"""Dequeue"""
|
|
num: int = self.peek()
|
|
# Move front pointer one position backward, returning to the head of the array if it exceeds the tail
|
|
self._front = (self._front + 1) % self.capacity()
|
|
self._size -= 1
|
|
return num
|
|
|
|
def peek(self) -> int:
|
|
"""Access front element"""
|
|
if self.is_empty():
|
|
raise IndexError("Queue is empty")
|
|
return self._nums[self._front]
|
|
|
|
def to_list(self) -> list[int]:
|
|
"""Return array for printing"""
|
|
res = [0] * self.size()
|
|
j: int = self._front
|
|
for i in range(self.size()):
|
|
res[i] = self._nums[(j % self.capacity())]
|
|
j += 1
|
|
return res
|
|
|
|
|
|
"""Driver Code"""
|
|
if __name__ == "__main__":
|
|
# Initialize queue
|
|
queue = ArrayQueue(10)
|
|
|
|
# Element enqueue
|
|
queue.push(1)
|
|
queue.push(3)
|
|
queue.push(2)
|
|
queue.push(5)
|
|
queue.push(4)
|
|
print("Queue queue =", queue.to_list())
|
|
|
|
# Access front element
|
|
peek: int = queue.peek()
|
|
print("Front element peek =", peek)
|
|
|
|
# Element dequeue
|
|
pop: int = queue.pop()
|
|
print("Dequeued element pop =", pop)
|
|
print("Queue after dequeue =", queue.to_list())
|
|
|
|
# Get the length of the queue
|
|
size: int = queue.size()
|
|
print("Queue length size =", size)
|
|
|
|
# Determine if the queue is empty
|
|
is_empty: bool = queue.is_empty()
|
|
print("Is the queue empty =", is_empty)
|
|
|
|
# Test circular array
|
|
for i in range(10):
|
|
queue.push(i)
|
|
queue.pop()
|
|
print("In the ", i, "th round of enqueue + dequeue, queue = ", queue.to_list())
|