Python to Java translation
- by obelix1337
Hello,
i get quite short code of algorithm in python, but i need to translate it to Java. I didnt find any program to do that, so i will really appreciate to help translating it.
I learned python a very little to know the idea how algorithm work.
The biggest problem is because in python all is object and some things are made really very confuzing like
sum(self.flow[(source, vertex)] for
vertex, capacity in
self.get_edges(source))
and "self.adj" is like hashmap with multiple values which i have no idea how to put all together. Is any better collection for this code in java?
code is:
[CODE]
class FlowNetwork(object):
def __init__(self):
self.adj, self.flow, = {},{}
def add_vertex(self, vertex):
self.adj[vertex] = []
def get_edges(self, v):
return self.adj[v]
def add_edge(self, u,v,w=0):
self.adj[u].append((v,w))
self.adj[v].append((u,0))
self.flow[(u,v)] = self.flow[(v,u)] = 0
def find_path(self, source, sink, path):
if source == sink:
return path
for vertex, capacity in self.get_edges(source):
residual = capacity - self.flow[(source,vertex)]
edge = (source,vertex,residual)
if residual > 0 and not edge in path:
result = self.find_path(vertex, sink, path + [edge])
if result != None:
return result
def max_flow(self, source, sink):
path = self.find_path(source, sink, [])
while path != None:
flow = min(r for u,v,r in path)
for u,v,_ in path:
self.flow[(u,v)] += flow
self.flow[(v,u)] -= flow
path = self.find_path(source, sink, [])
return sum(self.flow[(source, vertex)] for vertex, capacity in self.get_edges(source))
g = FlowNetwork()
map(g.add_vertex, ['s','o','p','q','r','t'])
g.add_edge('s','o',3)
g.add_edge('s','p',3)
g.add_edge('o','p',2)
g.add_edge('o','q',3)
g.add_edge('p','r',2)
g.add_edge('r','t',3)
g.add_edge('q','r',4)
g.add_edge('q','t',2)
print g.max_flow('s','t')
[/CODE]
result of this example is "5".
algorithm find max flow in graph(linked list or whatever) from source vertex "s" to destination "t".
Many thanx for any idea
