有向图找环的python实现

最新推荐文章于 2025-03-19 08:00:20 发布

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最新推荐文章于 2025-03-19 08:00:20 发布

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分类专栏： python 文章标签：有向图环

本文链接：https://blog.youkuaiyun.com/voidcc/article/details/31805825

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本文介绍了如何使用Python算法来检测有向图中的环，详细解析了算法思路，并提供了具体的实现代码参考。

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算法参考：http://blog.youkuaiyun.com/xw13106209/article/details/6538634

def findcircle(G):
    """
    color = 0 hasn't been visited
    color = -1 be visited once
    color = 1 has been dfs, all children of the spot has been visited
    """
    def dfs(G,i,color,is_DAG):
        if is_DAG == 0:
            pass
        else:
            r = len(G)
            color[i] = -1  #spot i has been visited
            #print 'color:',color
            #is_DAG = None
            for j in range(r):
                if G[i][j] != 0:
                    #print 'i:',i
                    #print 'j:',j
                    if color[j] == -1:
                        is_DAG = 0
                        break
                    elif