![](/img/trans.png)
[英]Using BFS/DFS To Find Path With Maximum Weight in Directed Acyclic Graph
[英]Find vertices along maximum cost path in directed graph
我有一個像這樣的加權有向圖:
我想從頭到尾沿着最大成本路徑找到頂點列表。
在這個例子中,我應該得到:
'enableBrowserExtension' -> 'newWindow' -> 'newTab' -> 'startPage' -> 'typed' -> 'selectTab' -> 'clickTextField' -> 'changeField-frullatore' -> 'clickButton-VAI' -> 'submit' -> 'formSubmit' -> 'mouseClick' -> 'link'
我想這個代碼中發現在這里:
import networkx as nx
def inverse_weight(graph, weight='weight'):
copy_graph = graph.copy()
for n, eds in copy_graph.adjacency():
for ed, eattr in eds.items():
copy_graph[n][ed][weight] = eattr[weight] * -1
return copy_graph
def longest_path_and_length(graph, s, t, weight='weight'):
i_w_graph = inverse_weight(graph, weight)
path = nx.dijkstra_path(i_w_graph, s, t)
length = nx.dijkstra_path_length(i_w_graph, s, t) * -1
return path, length
if __name__ == '__main__':
DG = nx.DiGraph()
DG.add_edge('enableBrowserExtension', 'enableBrowserExtension', weight=3)
DG.add_edge('enableBrowserExtension', 'newWindow', weight=1)
DG.add_edge('newWindow', 'newTab', weight=1)
DG.add_edge('newTab', 'startPage', weight=1)
DG.add_edge('startPage', 'typed', weight=1)
DG.add_edge('typed', 'selectTab', weight=2)
DG.add_edge('selectTab', 'newTab', weight=1)
DG.add_edge('newTab', 'typed', weight=1)
DG.add_edge('typed', 'typed', weight=1)
DG.add_edge('selectTab', 'clickTextField', weight=2)
DG.add_edge('clickTextField', 'changeField', weight=1)
DG.add_edge('changeField', 'clickButton', weight=1)
DG.add_edge('clickButton', 'submit', weight=1)
DG.add_edge('submit', 'formSubmit', weight=1)
DG.add_edge('formSubmit', 'mouseClick', weight=1)
DG.add_edge('mouseClick', 'link', weight=2)
DG.add_edge('link', 'formSubmit', weight=1)
DG.add_edge('formSubmit', 'selectTab', weight=1)
DG.add_edge('selectTab', 'mouseClick', weight=1)
DG.add_edge('mouseClick', 'clickLink', weight=1)
DG.add_edge('clickLink', 'link', weight=1)
DG.add_edge('link', 'mouseClick', weight=2)
DG.add_edge('mouseClick', 'changeField', weight=1)
DG.add_edge('changeField', 'mouseClick', weight=1)
DG.add_edge('mouseClick', 'selectTab', weight=1)
path, length = longest_path_and_length(DG, 'enableBrowserExtension', 'link')
但我收到錯誤:
ValueError: ('Contradictory paths found:', 'negative weights?')
我也試過這個java代碼,但它只以整數形式返回總最大成本,我想要沿着路徑的頂點的名稱。
有沒有辦法來解決這個問題?
由於圖中存在正值循環,因此最大成本路徑是無限的。 您需要刪除瑣碎的循環並完善其他循環。 也許您有一個未實現的要求,即沒有節點被多次訪問?
無限循環的各種方式是你得到“矛盾路徑”的原因。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.