def test_construction(backend):
h = PairingHeap(backend=backend)
assert h.findmin() is None
with py.test.raises(StandardError):
h.deletemin()
h = PairingHeap(backend=backend, items=xrange(5))
assert h.findmin() == 0
for x in xrange(5):
assert h.getkey(x) == x
for x in xrange(5):
assert h.deletemin() == x
alphabet = 'abcdefghij'
h = PairingHeap(backend=backend,
keys=dict(zip(alphabet, xrange(len(alphabet)))))
assert h.findmin() == 'a'
for x in alphabet:
assert h.getkey(x) == ord(x) - ord('a')
for x in alphabet:
assert h.deletemin() == x
def sorted(self, iterable, cmp=cmp, key=None, reverse=False):
from yaupon.data_structures.pairing_heaps import PairingHeap
if reverse:
mycmp = lambda x,y : -1 * cmp(x, y)
else:
mycmp = cmp
heap = PairingHeap(backend=self, cmp=mycmp)
for item in iterable:
item_key = heap.getkey(item)
if item_key is not None:
heap.modifykey(item, (item_key[0], item_key[1] + 1))
else:
item_key = item
if key is not None:
item_key = key(item)
heap.insert(item, (item_key, 1))
while heap:
min_key = heap.findminkey()
min_item = heap.deletemin()
for i in xrange(min_key[1]):
yield min_item