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DSA/GA3/tree.py

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Python
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2019-05-13 14:00:21 +00:00
#!/usr/bin/env python3
# vim: set ts=2 sw=2 et tw=80:
import sys
class Node:
def __init__(self, k):
self.key = k
self.left = None
self.right = None
self.parent = None
def set_left(self, kNode):
kNode.parent = self
self.left = kNode
def set_right(self, kNode):
kNode.parent = self
self.right = kNode
def search(tree, k):
if tree is None:
return None
elif tree.key == k:
return tree
elif k < tree.key:
return search(tree.left, k)
else:
return search(tree.right, k)
def insert(t, k):
insert_node(t, Node(k))
def insert_node(t, node):
if node.key < t.key:
if t.left is None:
t.set_left(node)
else:
insert_node(t.left, node)
else:
if t.right is None:
t.set_right(node)
else:
insert_node(t.right, node)
def root_insert(t, k):
if t is None:
return k
if k.key > t.key:
t.set_right(root_insert(t.right, k))
return left_rotate(t)
else:
t.set_left(root_insert(t.left, k))
return right_rotate(t)
def unlink_me(node, to_link):
if node.parent == None:
tr = node
node.key = to_link.key
node.left = to_link.left
node.right = to_link.right
return node
elif node.parent.left == node:
node.parent.left = to_link
return to_link
else:
node.parent.right = to_link
return to_link
def delete(t, k):
to_delete = search(t, k)
if to_delete is None:
return
elif to_delete.left is None:
unlink_me(to_delete, to_delete.right)
elif to_delete.right is None:
unlink_me(to_delete, to_delete.left)
else:
if abs(to_delete.left.key - to_delete.key) < abs(to_delete.right.key -
to_delete.key):
ins = to_delete.right
new_branch = unlink_me(to_delete, to_delete.left)
insert_node(new_branch, ins)
else:
ins = to_delete.left
new_branch = unlink_me(to_delete, to_delete.right)
insert_node(new_branch, ins)
###############################################################################
# Code for printing trees, ignore this
class Canvas:
def __init__(self, width):
self.line_width = width
self.canvas = []
def put_char(self, x, y, c):
if x < self.line_width:
pos = y * self.line_width + x
l = len(self.canvas)
if pos < l:
self.canvas[pos] = c
else:
self.canvas[l:] = [' '] * (pos - l)
self.canvas.append(c)
def print_out(self):
i = 0
for c in self.canvas:
sys.stdout.write(c)
i = i + 1
if i % self.line_width == 0:
sys.stdout.write('\n')
if i % self.line_width != 0:
sys.stdout.write('\n')
def print_binary_r(t, x, y, canvas):
max_y = y
if t.left is not None:
x, max_y, lx, rx = print_binary_r(t.left, x, y + 2, canvas)
x = x + 1
for i in range(rx, x):
canvas.put_char(i, y + 1, '/')
middle_l = x
for c in str(t.key):
canvas.put_char(x, y, c)
x = x + 1
middle_r = x
if t.right is not None:
canvas.put_char(x, y + 1, '\\')
x = x + 1
x0, max_y2, lx, rx = print_binary_r(t.right, x, y + 2, canvas)
if max_y2 > max_y:
max_y = max_y2
for i in range(x, lx):
canvas.put_char(i, y + 1, '\\')
x = x0
return (x, max_y, middle_l, middle_r)
def print_tree(t):
print_w(t, 80)
def print_w(t, width):
canvas = Canvas(width)
print_binary_r(t, 0, 0, canvas)
canvas.print_out()
###############################################################################
if __name__ == "__main__":
args = [x for x in sys.argv[1:]]
T = Node(int(args[0]))
for i in range(1, len(args)):
if args[i] == '|':
break
print_tree(T)
print("\nInsert " + str(args[i]) + ":")
insert(T, int(args[i]))
for i in range(i+1, len(args)):
print_tree(T)
print("\nDelete " + str(args[i]) + ":")
delete(T, int(args[i]))
print_tree(T)