def __init__(self, sourceCollection = None):
# Now tracks occupied cells for rehashing if necessary.
self._array = Array(HashSet.DEFAULT_CAPACITY)
self._foundNode = self._priorNode = None
self._index = -1
self._occupiedCells = 0
AbstractCollection.__init__(self, sourceCollection)
def __init__(self, sourceDictionary=None):
"""Will copy items to the collection from sourceDictionary
if it's present."""
self._array = Array(HashDict.DEFAULT_CAPACITY)
self._foundNode = self._priorNode = None
self._index = -1
AbstractDict.__init__(self, sourceDictionary)
def pop(self):
"""Removes and returns the item at the front of the queue.
Precondition: the queue is not empty.
Raises: KeyError if queue is empty.
Postcondition: the front item is removed from the queue."""
if self.isEmpty():
raise KeyError("Queue is empty")
data = self._items[self._front]
self._size -= 1
if self.isEmpty(): self._front = self._rear = -1
elif self._front == len(self._items) - 1:
self._front = 0
else:
self._front += 1
if len(self) <= .25 * len(self._items) and \
ArrayQueue.DEFAULT_CAPACITY <= len(self._items) // 2:
tempArray = Array(len(self._items) // 2)
i = 0
for item in self:
tempArray[i] = item
i += 1
self._items = tempArray
if not self.isEmpty():
self._front = 0
self._rear = len(self) - 1
return data
def add(self, item):
"""Inserts item at rear of the queue."""
# Resize array if full
if len(self) == len(self._items):
temp = Array(len(self._items) * 2)
# Copy so that front is at 0 and rear is at len(self) - 1
i = 0
# Copy data from position front through the end of the array
for j in range(self._front, len(self)):
temp[i] = self._items[j]
i += 1
if self._rear < len(self) - 1:
# Copy data from position 0 through the rear
for j in range(0, self._rear + 1):
temp[i] = self._items[j]
i += 1
self._items = temp
# Normalize front and rear
self._front = 0
self._rear = len(self) - 1
if self.isEmpty():
self._front = self._rear = 0
elif self._rear == len(self._items) - 1:
self._rear = 0
else:
self._rear += 1
self._items[self._rear] = item
self._size += 1
def remove(self, item):
"""Precondition: item is in self.
Raises: KeyError if item in not in self.
Postcondition: item is removed from self."""
# Check precondition and raise if necessary
if not item in self:
raise KeyError(str(item) + " not in bag")
# Search for the index of the target item
targetIndex = 0
for targetItem in self:
if targetItem == item:
break
targetIndex += 1
# Shift items to the left of target up by one position
for i in range(targetIndex, len(self) - 1):
self._items[i] = self._items[i + 1]
# Decrement logical size
self._size -= 1
# Check array memory here and decrease it if necessary
if len(self) < len(self._items) // 3 and \
2 * len(self) >= ArrayBag.DEFAULT_CAPACITY:
temp = Array(len(self._items) // 2)
for i in range(len(self)):
temp[i] = self[i]
self._items = temp
def rehash(self):
"""Resizes the dictionary and rehashes its keys."""
if self.loadFactor() > 0.5:
items = self.items()
self._array = Array(len(self._array) * 2)
self._size = 0
for item in items:
self[item.key] = item.value
def __init__(self, sourceCollection=None):
"""Sets the initial state of self, which includes the
contents of sourceCollection, if it's present."""
self._items = Array(ArrayBag.DEFAULT_CAPACITY)
self._size = 0
if sourceCollection:
for item in sourceCollection:
self.add(item)
def _resize(self, array, logicalSize):
"""If the array needs resizing, resizes and returns
the new array. Otherwise, returns the olf array."""
temp = None
# If array is full
if len(array) == logicalSize:
temp = Array(2 * len(array))
# If array is wasting space
elif logicalSize <= .25 * len(array) and \
len(array) >= ArrayList.DEFAULT_CAPACITY:
temp = Array(round(.5 * len(array)))
# None of the above
else:
return array
# Copy items to new array
for i in range(logicalSize):
temp[i] = array[i]
return temp
def push(self, item):
"""Inserts item at top of the stack."""
# Resize array here if necessary
if len(self) == len(self._items):
temp = Array(2 * len(self))
for i in range(len(self)):
temp[i] = self._items[i]
self._items = temp
self._items[len(self)] = item
self._size += 1
def add(self, item):
"""Adds item to self."""
# Check array memory here and increase it if necessary
if len(self) == len(self._items):
temp = Array(2 * len(self))
for i in range(len(self)):
temp[i] = self[i]
self._items = temp
self._items[len(self)] = item
self._size += 1
def pop(self):
"""Removes and returns the item at the top of the stack.
Precondition: the stack is not empty.
Raises: KeyError if stack is empty.
Postcondition: the top item is removed from the stack."""
if self.isEmpty():
raise KeyError("The stack is empty")
oldItem = self._items[len(self) - 1]
self._size -= 1
# Resize the array here if necessary
if len(self) <= len(self._items) // 4 and \
len(self._items) >= 2 * ArrayStack.DEFAULT_CAPACITY:
temp = Array(len(self._items) // 2)
for i in range(len(self)):
temp[i] = self._items[i]
self._items = temp
return oldItem
def __init__(self, sourceCollection=None):
"""Sets the initial state of self, which includes the
contents of sourceCollection, if it's present."""
self._items = Array(ArrayList.DEFAULT_CAPACITY)
AbstractList.__init__(self, sourceCollection)
def _rehash(self):
items = list(self)
self._array = Array(len(self._array) * 2)
self._size = 0
for item in items:
self.add(item)
def clear(self):
"""Makes self become empty."""
self._size = 0
self._array = Array(HashSet.DEFAULT_CAPACITY)
def clear(self):
"""Makes self become empty."""
self._size = 0
self._front = self._rear = -1
self._items = Array(ArrayQueue.DEFAULT_CAPACITY)
def clear(self):
"""Makes self become empty."""
self._size = 0
self._items = Array(ArrayList.DEFAULT_CAPACITY)
def __init__(self, rows, columns, fillValue=None):
self._data = Array(rows)
for row in range(rows):
self._data[row] = Array(columns, fillValue)