def test_push():
from binheap import BinHeap
sample_list = [16, 14, 15, 9, 7, 6, 5, 1, 2, 3]
bh = BinHeap(sample_list)
sample_list.append(4)
bh.push(4)
assert bh._container == sample_list
class PriorityQ(object):
"""Class for implementing a priority queue."""
def __init__(self):
self._heap = BinHeap(order='min')
self._cumulative_idx = 0
def insert(self, pri, val):
"""Insert a value at the end of the priority queue."""
self._heap.push((pri, self._cumulative_idx, val))
self._cumulative_idx += 1
def pop(self):
"""Remove and return the value at the root of the priority queue."""
try:
result = self._heap.pop()
return result[2]
except IndexError:
raise IndexError("Cannot pop from empty queue.")
def peek(self):
"""Return the value of at the root of the priority queue."""
try:
return self._heap._heap_list[0][2]
except IndexError:
return None
class PriorityQ(object):
"""Class for implementing a priority queue."""
def __init__(self):
self._heap = BinHeap(order='min')
self._cumulative_idx = 0
def insert(self, pri, val):
"""Insert a value at the end of the priority queue."""
self._heap.push((pri, self._cumulative_idx, val))
self._cumulative_idx += 1
def pop(self):
"""Remove and return the value at the root of the priority queue."""
try:
result = self._heap.pop()
return result[2]
except IndexError:
raise IndexError("Cannot pop from empty queue.")
def peek(self):
"""Return the value of at the root of the priority queue."""
try:
return self._heap._heap_list[0][2]
except IndexError:
return None
def test_pull(full_heap, empty_heap):
full_heap.pop()
assert len(full_heap) == 11
assert helper(full_heap) is True
full_heap.pop()
assert len(full_heap) == 10
assert helper(full_heap) is True
empty_heap = BinHeap()
with pytest.raises(LookupError):
empty_heap.pop()
empty_heap.push(2)
assert empty_heap.pop() == 2
with pytest.raises(LookupError):
empty_heap.pop()
class Priorityq(object):
def __init__(self):
self.binheap = BinHeap()
self._count = 0
def insert(self, priority, val):
new_node = Node(priority, val, self._count)
self.binheap.push(new_node)
self._count += 1
def pop(self):
return_node = self.binheap.pop()
return return_node.val
def peek(self):
return self.binheap[0].val
def full_heap():
heap = BinHeap()
heap.push(5)
heap.push(4)
heap.push(10)
heap.push(7)
heap.push(2)
return heap
class PriorityQ(object):
"""Structure for values in a priorty queue.
Items added to the priority queue are given a priority. If not set
by the user, priority is set to be the lowest. When removing items,
higher priority items are removed before lower priority items.
"""
def __init__(self):
"""Construct a new priority queue."""
self._values = BinHeap()
self._min_priority = 0
def __len__(self):
"""Overwrite length to give us the amount of items in priority Q.
Get all the items from all the buckets in the priority Q.
"""
return sum(len(b) for b in self._all_values[1:])
@property
def _all_values(self):
return self._values._values
@property
def _size(self):
return self._values._size
def insert(self, val, priority=None):
"""Add a new value into the priority queue.
If no priority is given, uses current lowest priority.
"""
if priority is None:
priority = self._min_priority
if priority < self._min_priority:
self._min_priority = priority
try:
i = self._all_values.index(priority)
bucket = self._all_values[i]
bucket._values.enqueue(val)
except ValueError:
self._values.push(Bucket(priority, [val]))
def pop(self):
"""Remove the first value from priority Q.
If no values in bucket then bucket is removed.
"""
if len(self._all_values) < 2:
raise IndexError('Can not pop from empty priority Q.')
bucket = self._all_values[1]
result = bucket._values.dequeue()
if len(bucket._values) == 0:
self._values.pop()
return result
def peek(self):
"""Get the the most important item without removing it."""
if len(self._all_values) < 2:
return
bucket = self._all_values[1]
return bucket._values.peek()
def test_pop_last():
heap = BinHeap()
heap.push(5)
assert heap.pop() == 5
assert heap.list == []
def test_pop_one_child():
heap = BinHeap()
heap.push(5)
heap.push(10)
assert heap.pop() == 5
def test_push_more():
heap = BinHeap()
heap.push(5)
heap.push(4)
assert heap.list[0] == 4
assert heap.list[1] == 5
def test_push():
heap = BinHeap()
heap.push(5)
assert heap.list[0] == 5
