# ! /usr/bin/env python
# -*- coding: utf-8 -*-
'''
@author: liudaoqiang
@file: studycase
@time: 2018/8/31 7:44
'''
import time
class Array(object):
"""Represent Array"""
def __init__(self, capacity, fillValue=None):
self._items = list()
for count in range(capacity):
self._items.append(fillValue)
def __iter__(self):
return iter(self._items)
def __len__(self):
return len(self._items)
def __str__(self):
return str(self._items)
def __getitem__(self, index):
return self._items[index]
def __setitem__(self, index, newItem):
self._items[index] = newItem
class Node(object):
def __init__(self, data, next=None):
self.data = data
self.next = next
def __iter__(self):
# 链表必须是可迭代的，才能被加入到LinkedBag实例对象中
cursor = self
while cursor != None:
yield cursor.data
cursor = cursor.next
class LinkedBag(object):
def __init__(self, sourceCollection=None):
self._items = None
self._size = 0
if sourceCollection != None:
for item in sourceCollection:
self.add(item)
def isEmpty(self):
return len(self) == 0
def __len__(self):
return self._size
def __add__(self, other):
result = LinkedBag(self)
for item in other:
result.add(item)
return result
def __eq__(self, other):
if self == other:
return True
if type(self) != type(other) or \
len(self) != len(other):
return False
for item in self:
if item not in other:
return False
return True
def __str__(self):
return "{" + ", ".join(map(str, self)) + "}"
def __iter__(self):
cursor = self._items
while cursor != None:
yield cursor.data
cursor = cursor.next
def add(self, item):
self._items = Node(item, self._items)
self._size += 1
def removeItem(self, targetItem):
"""删除元素"""
if targetItem not in self:
raise KeyError(str(targetItem) + "not in bag")
probe = self._items
trailor = None
for item in self:
if targetItem == item:
break
trailor = probe
probe = probe.next
if probe == self._items: # 如果probe没有移动
self._items = self._items.next # 要删除的item就是第一个元素
else:
trailor.next = probe.next # trailor是probe的前一个节点，probe就是要删除的节点
self._size -= 1
def removeIndex(self, index):
"""删除下标对应的元素"""
if index >= self.__len__():
raise KeyError(index + "not in bag")
else:
probe = self._items
if index <= 0 or self._items.next == None:
self._items = self._items.next
else:
while index > 1 and self._items.next.next != None:
probe = probe.next
index -= 1
probe.next = probe.next.next
return self._items
class ArraySotrtedBag(object):
""" An array-based bag implementation"""
# Class variable
DEFAULT_CAPACITY = 10
# Constructor
def __init__(self, sourceCollection=None):
"""Sets the initial state of self, which includes the contents of sourceCollection,
if it`s present """
self._items = Array(ArraySotrtedBag.DEFAULT_CAPACITY)
self._size = 0
if sourceCollection:
for item in sourceCollection:
self.add(item)
# Accessor methods
def isEmpty(self):
"""Returns True if len(self) == 0, or False otherwise."""
return len(self) == 0
def __len__(self):
"""Returns the logical number of items in self"""
return self._size # 返回逻辑大小
# Mutator methods
def clear(self):
"""Makes self become empty"""
self._size = 0
self._items = Array(ArraySotrtedBag.DEFAULT_CAPACITY)
def add(self, item):
"""Add item to self"""
# check array memmory here and increase it if necessary
# 插入排序
if self._size == 0:
self._items[0] = item
else:
index = len(self) - 1
while index >= 0:
if self._items[index] > item:
self._items[index + 1] = self._items[index]
index -= 1
else:
break
self._items[index + 1] = item
self._size += 1
# 当数组的逻辑大小超过ArrayBag.DEFAULT_CAPACITY=10(物理大小)时，增加数组容量
if self._size == ArraySotrtedBag.DEFAULT_CAPACITY:
temp = Array(ArraySotrtedBag.DEFAULT_CAPACITY + 1)
for i in range(len(self) - 1):
temp[i] = self._items[i]
self._items = temp
def __iter__(self):
"""Supports iteration over a view of self"""
cursor = 0
while cursor < len(self):
yield self._items[cursor] # 通过yield方法，将每一项都发送给for循环调用
cursor += 1
def __str__(self):
"""returns the string representation of self"""
return "{" + ", ".join(map(str, self)) + "}"
def __add__(self, other):
"""returns a new bag containing the contents of self and other"""
result = ArraySotrtedBag(self)
for item in other:
result.add(item)
return result
def __eq__(self, other):
"""returns true if self equals other, or false otherwise"""
if self is other: return True
if type(self) != type(other) or \
len(self) != len(other):
return False
# for item in self:
# if item not in other:
# return False
# 用for和迭代器两种迭代可以将
otherIter = iter(other)
for item in self:
if item != next(otherIter):
return False
return True
def remove(self, item):
"""check precondition and raise if necessary"""
if item not in self:
raise KeyError(str(item) + " not in bag")
targetIndex = 0
for targetItem in self:
if targetItem == item:
break
targetIndex += 1
for i in range(targetIndex, len(self) - 1):
self._items[targetIndex] = self._items[targetIndex + 1]
self._size -= 1
# 当数组逻辑大小小于或等于物理大小的四分之一，并且其物理大小至少
# 是创建数组的默认容量的两倍的时候。
if self._size <= ArraySotrtedBag.DEFAULT_CAPACITY:
temp = Array(ArraySotrtedBag.DEFAULT_CAPACITY // 2)
for i in range(self._size):
temp[i] = self._items[i]
self._items = temp
def __contains__(self, item):
# 二叉搜索已经排好序的数组
left = 0
right = len(self) - 1
while left < right:
middle = (left + right) // 2
if item == self._items[middle]:
return True
elif item < self._items[middle]:
right = middle - 1
else:
left = middle + 1
return False
def insertSorted(self):
length = len(self)
i = 1
while i < length:
insertItem = self._items[i]
j = i - 1
while j > 0:
if self._items[j] > insertItem:
self._items[j + 1] = self._items[j]
j -= 1
else:
break
self._items[j + 1] = insertItem
i += 1
if __name__ == "__main__":
lyst = list(range(6, 1, -1))
# print(lyst)
head = None
for count in range(5):
head = Node(lyst[count], head)
probe = head
linkedBag = LinkedBag(probe)
linkedBag.removeItem(4) # {6, 5, 3, 2}
linkedBag.removeIndex(1) # {6, 3, 2}
print(linkedBag)
"""
2 3 4 5 6
"""
probe = head
while probe != None:
print(probe.data, end=" ")
probe = probe.next
print() # 添加一个换行符
arraySortedBag = ArraySotrtedBag(lyst)
# arraySortedBag: {2, 3, 4, 5, 6}
print("arraySortedBag:", arraySortedBag)
print(2 in arraySortedBag) # True
print(1 in arraySortedBag) # False
# add方法按顺序添加项
# {2, 3, 4, 5, 6, 9, 10}
arraySortedBag.add(10)
arraySortedBag.add(9)
print(arraySortedBag)
# 题目1
"""
__eq__实现1
def __eq__(self, other):
if self is other: return True
if type(self) != type(other) or \
len(self) != len(other):
return False
# for item in self:
# if item not in other:
# return False
# 用for和迭代器两种迭代可以将
otherIter = iter(other)
for item in self:
if item != next(otherIter):
return False
return True
# 返回
{2, 3, 4, 5, 6, 9, 10}
{2, 3, 3, 4, 5}
False
interval time: 6.564099871138514e-06 # 时间更短
__eq__实现2
def __eq__(self, other):
if self is other: return True
if type(self) != type(other) or \
len(self) != len(other):
return False
for item in self:
if item not in other:
return False
# 用for和迭代器两种迭代可以将
# otherIter = iter(other)
# for item in self:
# if item != next(otherIter):
# return False
return True
# 返回
{2, 3, 4, 5, 6, 9, 10}
{2, 3, 3, 4, 5}
False
interval time: 9.435893564761614e-06
"""
lyst1 = lyst
lyst1[0] = 3
arraySortedBag1 = ArraySotrtedBag(lyst1)
print(arraySortedBag1)
start = time.clock()
print(arraySortedBag1 == arraySortedBag)
end = time.clock()
print("interval time:", end)
6.6题目
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转载自blog.csdn.net/liudaoqiang_tj/article/details/82312949
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