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main.py
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import sys
sys.setrecursionlimit(100000)
class Node:
def __init__(self, key, parent):
self.key = key
self.left = None
self.right = None
self.color = 'r'
self.parent = parent
def getSibling(self):
if self == None or self.parent == None:
return None
if self == self.parent.left:
return self.parent.right
return self.parent.left
def getAunt(self):
if self == None:
return None
return self.parent.getSibling()
def hasTwoChildren(self):
return (self.right != None) and (self.left != None)
def child(self):
return self.right if self.right != None else self.left
def hasTwoBlackChildren(self):
return (self.child() == None) or (self.hasTwoChildren() and (self.left.color == 'b' and self.right.color == 'b')) or (self.child().color == 'b')
def kill(self): # replace node with its only child, then kill it
if self != None:
if self.child() != None:
self.child().parent = self.parent
if self == self.parent.left:
self.parent.left = self.child()
else:
self.parent.right = self.child()
class RBT:
def __init__(self):
self.root = None
def initSearch(self, node, key):
if node == None:
return None
if node.key == key:
return node
if node.key > key:
return self.initSearch(node.left, key)
return self.initSearch(node.right, key)
def initMin(self, node):
if node.left == None:
return node
return self.initMin(node.left)
def min(self):
if self.root.left == None:
return self.root
return self.initMin(self.root.left)
def initMax(self, node):
if node.right == None:
return node
return self.initMax(node.right)
def max(self):
if self.root.right == None:
return self.root
return self.initMax(self.root.right)
def predecessor(self, node):
if node.left != None:
return self.initMax(node.left)
par = node.parent
while par != None and node == par.left:
node = par
par = par.parent
return par
def successor(self, node):
if node.right != None:
return self.initMin(node.right)
par = node.parent
while par != None and node == par.right:
node = par
par = par.parent
return par
def search(self, key):
if self.root == None:
return None
if self.root.key == key:
return self.root
if self.root.key > key:
return self.initSearch(self.root.left, key)
return self.initSearch(self.root.right, key)
def rotate(self, node, direction):
if direction == "left":
node.right.parent = node.parent
if node == self.root:
self.root = node.right
elif node == node.parent.left:
node.parent.left = node.right
else:
node.parent.right = node.right
right_child = node.right
node.right = right_child.left
if node.right != None:
node.right.parent = node
right_child.left = node
node.parent = right_child
else:
node.left.parent = node.parent
if node == self.root:
self.root = node.left
elif node == node.parent.left:
node.parent.left = node.left
else:
node.parent.right = node.left
left_child = node.left
node.left = left_child.right
if node.left != None:
node.left.parent = node
left_child.right = node
node.parent = left_child
def fixup(self, node):
if node == self.root:
node.color = 'b'
return
if node.parent.color == 'r':
if node.getAunt() == None or node.getAunt().color == 'b':
ggrandpa = node.parent.parent.parent
if ggrandpa != None:
if node.parent.parent == ggrandpa.left:
is_left_child = True
else:
is_left_child = False
if node == node.parent.left and node.parent == node.parent.parent.left:
self.rotate(node.parent.parent, "right")
elif node == node.parent.right and node.parent == node.parent.parent.right:
self.rotate(node.parent.parent, "left")
elif node == node.parent.right and node.parent == node.parent.parent.left:
grandpa = node.parent.parent
self.rotate(node.parent, "left")
self.rotate(grandpa, "right")
else:
grandpa = node.parent.parent
self.rotate(node.parent, "right")
self.rotate(grandpa, "left")
if ggrandpa == None:
self.root.color = 'b'
self.root.left.color = 'r'
self.root.right.color = 'r'
elif is_left_child == True:
ggrandpa.left.color = 'b'
ggrandpa.left.left.color = 'r'
ggrandpa.left.right.color = 'r'
else:
ggrandpa.right.color = 'b'
ggrandpa.right.left.color = 'r'
ggrandpa.right.right.color = 'r'
else:
node.parent.color = 'b'
node.getAunt().color = 'b'
node.parent.parent.color = 'r'
return self.fixup(node.parent.parent)
else:
return
def initInsert(self, node, key):
if node.key > key:
if node.left == None:
newNode = Node(key, node)
node.left = newNode
return newNode
return self.initInsert(node.left, key)
if node.right == None:
newNode = Node(key, node)
node.right = newNode
return newNode
return self.initInsert(node.right, key)
def insert(self, key):
if self.root == None:
newNode = Node(key, None)
newNode.color = 'b'
self.root = newNode
return newNode
if self.root.key > key:
if self.root.left == None:
newNode = Node(key, self.root)
self.root.left = newNode
return newNode
newNode = self.initInsert(self.root.left, key)
else:
if self.root.right == None:
newNode = Node(key, self.root)
self.root.right = newNode
return newNode
newNode = self.initInsert(self.root.right, key)
self.fixup(newNode)
def BFS(self):
output = []
output.append(str(self.root.key) + self.root.color)
Q = []
Q.append(self.root)
cur = 0
while len(Q) != cur:
v = Q[cur]
cur += 1
if v.left != None:
output.append(str(v.left.key) + v.left.color)
Q.append(v.left)
if v.right != None:
output.append(str(v.right.key) + v.right.color)
Q.append(v.right)
print(*output)
def doubleBlackCycle(self, child):
nil = None
if child.key == None:
nil = child
while(True):
sib = child.getSibling()
if sib != None and sib.color == 'r': # case 1
if child == child.parent.left:
self.rotate(child.parent, "left")
else:
self.rotate(child.parent, "right")
child.parent.color = 'r'
sib.color = 'b'
else:
if sib == None or sib.hasTwoBlackChildren(): # case 2
if sib != None:
sib.color = 'r'
if child != self.root:
if child.parent.color == 'r':
child.parent.color = 'b'
break
else:
child = child.parent
child.color = 'd'
else:
child.color = 'b'
break
else:
if child == child.parent.left:
if (sib.right == None or sib.right.color == 'b') and (sib.left != None and sib.left.color == 'r'): # case 3: goal is to have child.parent, sib and sib.child() [which is red] in a line
sib.left.color == 'b'
sib.color = 'r'
self.rotate(sib, "right")
sib = sib.parent
# case 4
self.rotate(child.parent, "left")
sib.color = sib.left.color
sib.right.color = 'b'
sib.left.color = 'b'
break
else:
if (sib.left == None or sib.left.color == 'b') and (sib.right != None and sib.right.color == 'r'): # case 3: goal is to have child.parent, sib and sib.child() [which is red] in a line
sib.right.color == 'b'
sib.color = 'r'
self.rotate(sib, "left")
sib = sib.parent
# case 4
self.rotate(child.parent, "right")
sib.color = sib.right.color
sib.left.color = 'b'
sib.right.color = 'b'
break
nil.kill()
def initDelete(self, node):
if node.color == 'r':
node.kill()
else:
if node.child() == None:
node.key = None
node.color = 'd' # double black
self.doubleBlackCycle(node)
else:
if node.child().color == 'r':
node.child().color == 'b'
node.kill()
else:
child = node.child()
node.kill()
child.color = 'd' # double black
self.doubleBlackCycle(child)
def delete(self, key):
node = self.search(key)
if node != None:
if node.hasTwoChildren():
if self.successor(node) != None and self.successor(node).color == 'r':
node.key = self.successor(node).key
self.initDelete(self.successor(node))
elif self.predecessor(node) != None and self.predecessor(node).color == 'r':
node.key = self.predecessor(node).key
self.initDelete(self.predecessor(node))
elif self.predecessor(node) != None:
node.key = self.predecessor(node).key
self.initDelete(self.predecessor(node))
else:
node.key = self.predecessor(node).key
self.initDelete(self.predecessor(node))
else:
self.initDelete(node)
x = RBT()
while(True):
try:
op = list(input().split())
if op[0] == "insert":
x.insert(int(op[1]))
elif op[0] == "delete":
x.delete(int(op[1]))
elif op[0] == "print":
x.BFS()
except:
break