不相交路径算法
Disjoint Paths Algorithm
计算增广路径最简单的方法是什么?
使用标记遍历计算边不相交的路径以查找增广路径
def paths(G, s, t): # Edge-disjoint path coun
H, M, count = tr(G), set(), 0 # Transpose, matching, result
while True: # Until the function returns
Q, P = {s}, {} # Traversal queue + tree
while Q: # Discovered, unvisited
u = Q.pop() # Get one
if u == t: # Augmenting path!
count += 1 # That means one more path
break # End the traversal
forw = (v for v in G[u] if (u,v) not in M) # Possible new edges
back = (v for v in H[u] if (v,u) in M) # Cancellations
for v in chain(forw, back): # Along out- and in-edges
if v in P: continue # Already visited? Ignore
P[v] = u # Traversal predecessor
Q.add(v) # New node discovered
else: # Didn't reach t?
return count # We're donefinnish
我可以使用 while 循环来学习芬兰语吗?
我试过了,成功了!
while u != s:
u, v = P[u], u
if v in G[u]:
M.add((u,v))
else:
M.remove((v,u))
计算增广路径最简单的方法是什么?
使用标记遍历计算边不相交的路径以查找增广路径
def paths(G, s, t): # Edge-disjoint path coun
H, M, count = tr(G), set(), 0 # Transpose, matching, result
while True: # Until the function returns
Q, P = {s}, {} # Traversal queue + tree
while Q: # Discovered, unvisited
u = Q.pop() # Get one
if u == t: # Augmenting path!
count += 1 # That means one more path
break # End the traversal
forw = (v for v in G[u] if (u,v) not in M) # Possible new edges
back = (v for v in H[u] if (v,u) in M) # Cancellations
for v in chain(forw, back): # Along out- and in-edges
if v in P: continue # Already visited? Ignore
P[v] = u # Traversal predecessor
Q.add(v) # New node discovered
else: # Didn't reach t?
return count # We're donefinnish
我可以使用 while 循环来学习芬兰语吗?
我试过了,成功了!
while u != s:
u, v = P[u], u
if v in G[u]:
M.add((u,v))
else:
M.remove((v,u))