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#!/usr/bin/env python3
# Challenge 129
#
# TASK #1 > Root Distance
# Submitted by: Mohammad S Anwar
# You are given a tree and a node of the given tree.
#
# Write a script to find out the distance of the given node from the root.
#
# Example 1:
# Tree:
# 1
# / \
# 2 3
# \
# 4
# / \
# 5 6
#
# Node: 6
# Output: 3 as the distance of given node 6 from the root (1).
#
# Node: 5
# Output: 3
#
# Node: 2
# Output: 1
#
# Node: 4
# Output: 2
# Example 2:
# Tree:
# 1
# / \
# 2 3
# / \
# 4 5
# \ /
# 6 7
# / \
# 8 9
#
# Node: 7
# Output: 3 as the distance of given node 6 from the root (1).
#
# Node: 8
# Output: 4
#
# Node: 6
# Output: 3
import fileinput
import re
import sys
class Node:
def __init__(self, value):
self.value = value
self.left = None
self.right = None
def __repr__(self):
return "Node(value: {}, left: {}, right: {})" \
.format(self.value, self.left, self.right)
def read_input():
lines = []
for line in fileinput.input():
lines.append(line)
return lines
def parse_subtree(lines, row, col):
def ch(row, col):
if row < 0 or row >= len(lines) or \
col < 0 or col >= len(lines[row]):
return ' '
else:
return lines[row][col]
tree = Node(int(lines[row][col]))
if ch(row + 1, col - 1) == '/':
tree.left = parse_subtree(lines, row + 2, col - 2)
if ch(row + 1, col + 1) == '\\':
tree.right = parse_subtree(lines, row + 2, col + 2)
return tree
def parse(lines):
found = re.search("^[ ]+\d", lines[0])
col = found.span()[1] - 1
return parse_subtree(lines, 0, col)
def root_dist(tree, value):
def subtree_dist(node, value, dist):
if value == node.value:
return dist
if node.left:
found = subtree_dist(node.left, value, dist+1)
if found > 0:
return found
if node.right:
found = subtree_dist(node.right, value, dist+1)
if found > 0:
return found
return -1
return subtree_dist(tree, value, 0)
value = int(sys.argv.pop())
tree = parse(read_input())
dist = root_dist(tree, value)
print(dist)
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