Created
October 11, 2013 01:37
-
-
Save nolanlum/6928366 to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import urllib2 | |
| import re | |
| import json | |
| from collections import namedtuple | |
| oper_pattern = re.compile(r"(abs|add|subtract|multiply)\(([-0-9]+)(?:,([-0-9]+))?\)") | |
| oper_map = { | |
| "abs" : lambda x, y: abs(long(x)), | |
| "add" : lambda x, y: long(x) + long(y), | |
| "subtract" : lambda x, y: long(x) - long(y), | |
| "multiply" : lambda x, y: long(x) * long(y) | |
| } | |
| url_base = "http://www.crunchyroll.com/tech-challenge/roaming-math/[email protected]/" | |
| Node = namedtuple('Node', ['previous', 'distance', 'visited']) | |
| def fetch_url(id): | |
| try: | |
| page = urllib2.urlopen(url_base + str(id)) | |
| children = [] | |
| for x in map(str.strip, page): | |
| if x == 'DEADEND' or x == 'GOAL': | |
| return x | |
| children.append(eval_expr(x)) | |
| return map(long, children) | |
| except: | |
| print "**ERROR 404: " + id | |
| def eval_expr(expr): | |
| m = oper_pattern.search(expr) | |
| if m is not None: | |
| repl = oper_map[m.group(1)](m.group(2), m.group(3)) | |
| expr = expr.replace(m.group(0), str(repl)) | |
| return eval_expr(expr) | |
| return expr | |
| # BFS then DFS | |
| def crawl(start): | |
| node_count = 1 | |
| goal = -1 | |
| shortest_path = None | |
| directed_cycle_count = 0 | |
| nodes_seen = {} | |
| crawl_queue = [start] | |
| # add source to seen list | |
| nodes_seen[start] = Node(None, 0, False) | |
| while len(crawl_queue) > 0: | |
| cur = crawl_queue.pop(0) | |
| children = fetch_url(cur) | |
| print "%s: %s" % (cur, children) | |
| if children == 'GOAL': | |
| goal = cur | |
| shortest_path = [] | |
| while cur in nodes_seen: | |
| shortest_path.insert(0, cur) | |
| cur = nodes_seen[cur].previous | |
| elif children == 'DEADEND': | |
| continue | |
| else: | |
| cur_distance = nodes_seen[cur].distance | |
| for x in children: | |
| if x not in nodes_seen: | |
| nodes_seen[x] = Node(cur, cur_distance + 1, False) | |
| node_count += 1 | |
| if x not in crawl_queue: | |
| crawl_queue.append(x) | |
| if x in nodes_seen and nodes_seen[x].visited: | |
| directed_cycle_count += 1 | |
| nodes_seen[cur] = nodes_seen[cur]._replace(visited=True) | |
| print json.dumps({ | |
| 'goal': goal, | |
| 'node_count' : len(nodes_seen), | |
| 'shortest_path' : shortest_path, | |
| 'directed_cycle_count' : directed_cycle_count | |
| }) | |
| crawl(587474L) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment