def test_lca(self):
tree = Tree({'A': 'xabxac', 'B': 'awyawxawxz'})
tree.prepare_lca()
self.assertEqual(
tree.lca(tree.nodemap['A'][1], tree.nodemap['B'][3]).id, 8)
self.assertEqual(
tree.lca(tree.nodemap['A'][0], tree.nodemap['B'][8]).id, 2)
self.assertEqual(
tree.lca(tree.nodemap['B'][1], tree.nodemap['B'][7]).id, 19)
self.assertEqual(
tree.lca(tree.nodemap['A'][0], tree.nodemap['B'][7]).id, 1)
class LongestPalindromeFinder(tk.Frame):
def __init__(self, master=None):
super().__init__(master=master)
tk.Label(self, text='Sequence').grid(row=0, column=0, sticky='w')
self.sequence_text = tk.Text(self)
self.sequence_text.grid(row=1, column=0, columnspan=2, sticky='nsew')
self.sequence_load_btn = tk.Button(
self, text='Choose file', command=self.choose_sequence_file)
self.sequence_load_btn.grid(row=2, column=1, sticky='e')
buttons_frame = tk.Frame(self)
self.run_btn = tk.Button(master=buttons_frame,
text='Run', command=self.run)
self.run_btn.grid(row=0, column=1)
self.export_btn = tk.Button(
master=buttons_frame, text='Export Tree', command=self.export_tree)
self.export_btn.grid(row=0, column=0)
buttons_frame.grid(row=3, column=0, columnspan=2, sticky='e')
for i in range(2):
self.grid_columnconfigure(i, weight=1)
for i in range(4):
self.grid_rowconfigure(i, weight=1)
self.sequence = None
self.tree = None
def choose_sequence_file(self):
filename = filedialog.askopenfilename(parent=self)
try:
self.sequence_text.delete(1.0, tk.END)
self.sequence_text.insert(tk.END, open(filename, 'r').read())
except FileNotFoundError:
messagebox.showwarning(
title='Bad file', message='No files selected')
def load_sequence(self):
self.sequence = self.sequence_text.get(1.0, tk.END).strip("\n ")
def construct_tree(self):
self.tree = Tree({1: self.sequence, 2: reversed(self.sequence)})
def initialize(self):
self.load_sequence()
if not self.sequence:
messagebox.showerror(
title='Bad input', message='Invalid input sequence')
return
self.construct_tree()
def run(self):
self.initialize()
result = str(self.find_the_longest_palindrome()).replace(' ', '')
output(result, 'longest_palindrome_found.txt')
def build_neighbor_leaves(self):
leaves = {}
def f(node):
if node.is_leaf():
leaves[(node.str_id, node.path.start)] = node
self.tree.root.post_order(f)
odd_neighbor_leaves = [(leaves[1, i], leaves[2, len(self.sequence) - 1 - i]) for i in range(len(self.sequence))]
even_neighbor_leaves = [(self.sequence[i], leaves[1, i + 1], leaves[2, len(self.sequence) + 1 - i]) for i in
range(1, len(self.sequence) - 1) if self.sequence[i - 1] == self.sequence[i]]
# neighbor_leaves = [(leaves[i, 0], leaves[2, 0])]
return odd_neighbor_leaves, even_neighbor_leaves
def find_the_longest_odd_palindrome(self, neighbor_leaves):
candidate_node = None
for node1, node2 in neighbor_leaves:
node = self.tree.lca(node1, node2)
if candidate_node is None or len(node) > len(candidate_node):
candidate_node = node
result = str(candidate_node).replace(' ', '')
result = (result[::-1])[:-1] + result
return result
def find_the_longest_even_palindrome(self, neighbor_leaves):
if not neighbor_leaves:
return ''
candidate_node = None
middle = None
for mid, node1, node2 in neighbor_leaves:
node = self.tree.lca(node1, node2)
if candidate_node is None or len(node) > len(candidate_node):
candidate_node = node
middle = mid
if candidate_node == self.tree.root:
candidate_node = ''
result = str(candidate_node).replace(' ', '')
result = result[::-1] + (middle * 2) + result
return result
def find_the_longest_palindrome(self):
odd_neighbor_leaves, even_neighbor_leaves = self.build_neighbor_leaves()
self.tree.prepare_lca()
odd_palindrome = self.find_the_longest_odd_palindrome(odd_neighbor_leaves)
even_palindrome = self.find_the_longest_even_palindrome(even_neighbor_leaves)
return max(odd_palindrome, even_palindrome, key=len)
def export_tree(self):
self.initialize()
filename = filedialog.asksaveasfilename(parent=self.master)
graphviz.Source(self.tree.to_dot()).render(
filename=filename, format='pdf', view=True, cleanup=True)
