def my_is_sorted(node):
s = stack()
explored = set()
curr_max = 0
s.push(node)
while not s.is_empty:
curr_node = s.peek()
explored.add(curr_node)
# Explore left subtree
if curr_node.left is not None and curr_node.left not in explored:
s.push(curr_node.left)
continue
# Compare to max
if curr_node.right not in explored:
if curr_node.value < curr_max:
return False
else:
curr_max = curr_node.value
# Explore right subtree
if curr_node.right is not None and curr_node.right not in explored:
s.push(curr_node.right)
continue
# All children explored
s.pop()
return True
def my_is_sorted(bt):
s = stack()
explored = set()
curr_max = 0
s.push(bt)
while not s.is_empty:
curr_node = s.peek()
explored.add(curr_node)
# Explore left subtree
if curr_node.left is not None and curr_node.left not in explored:
s.push(curr_node.left)
continue
# Compare to max
if curr_node.right not in explored:
if curr_node.value < curr_max:
return False
else:
curr_max = curr_node.value
# Explore right subtree
if curr_node.right is not None and curr_node.right not in explored:
s.push(curr_node.right)
continue
# All children explored
s.pop()
return True
def run():
print "stack TEST STARTING"
s = stack()
i = 0
for j in xrange(0, 1000):
s.push(j)
val = 999
while val >= 0:
x = s.pop()
assert x == val
val -= 1
assert s.empty()
print "stack TEST COMPLETED"
def run():
print "stack TEST STARTING"
s = stack()
i = 0
for j in xrange(0,1000):
s.push(j)
val = 999
while val >= 0:
x = s.pop()
assert x == val
val -= 1
assert s.empty()
print "stack TEST COMPLETED"
def canonical_is_sorted(node):
s = stack()
curr_max = 0
while (not s.is_empty) or (node is not None):
if node is not None:
s.push(node)
node = node.left
else:
node = s.pop()
if node.value < curr_max:
return False
else:
curr_max = node.value
node = node.right
return True
def canonical_is_sorted(node):
s = stack()
curr_max = 0
while (not s.is_empty) or (node is not None):
if node is not None:
s.push(node)
node = node.left
else:
node = s.pop()
if node.value < curr_max:
return False
else:
curr_max = node.value
node = node.right
return True
