65 lines
2.0 KiB
Python
65 lines
2.0 KiB
Python
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CYCLE_LIMIT = 3
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def rem_routes(routes):
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loop_routes = routes
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while len(loop_routes)>0:
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circ,paths,loop_routes = largest_loop(loop_routes)
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if not circ:
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break
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partial_paths = []
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partial_routes = loop_routes
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while len(partial_routes)>0:
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lp = longest_path(partial_routes)
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partial_paths.append((lp[-1].dst,lp[0].src))
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partial_routes = filter(lambda x:x not in lp,partial_routes)
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return partial_paths
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def route_deps(routes):
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routes_map = {}
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for r in routes:
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if routes_map.has_key(r.src):
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routes_map[r.src].append(r)
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else:
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routes_map[r.src]= [r]
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if not routes_map.has_key(r.dst):
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routes_map[r.dst]= []
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return routes_map
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def largest_loop(routes):
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deps = route_deps(routes)
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circ_paths = [find_loop(r.src,r.src,deps,set(),[]) for r in routes]
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circ,paths = max(circ_paths,key=lambda p:len(p[1]))
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# print filter(lambda p:not p[0],circ_paths)
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rem_paths = filter(lambda x:x not in paths,routes)
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return (circ,paths,rem_paths)
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def longest_path(routes):
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def route_path(r,deps):
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if not deps.has_key(r.dst) or len(deps[r.dst])==0:
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return [r]
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all_dep_paths = [([r]+route_path(rt,deps)) for rt in deps[r.dst]]
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rp = max(all_dep_paths,key=lambda p:len(p))
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return rp
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deps = route_deps(routes)
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all_paths = [route_path(r,deps) for r in routes]
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longest = max(all_paths,key=len)
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return longest
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def find_loop(elem,dep_elem,deps,checked,path):
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found_loop = False
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if dep_elem not in checked and deps.has_key(dep_elem):
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checked.add(dep_elem)
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for c in deps[dep_elem]:
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path.append(c)
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if elem == c.dst and len(path) <= CYCLE_LIMIT:
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found_loop = True
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break
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(loop,path) = find_loop(elem,c.dst,deps,checked,path)
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if loop:
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found_loop = True
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break
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else:
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del(path[-1])
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return (found_loop,path)
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