之前学算法经常不求甚解，懒癌发作不敲代码不实践，到头来自己挖的坑还是得自己填，我会陆续更新代码，本文大量代码来自互联网，能找到出处的我会尽量贴上出处

广度优先搜索、深度优先搜索

http://www.cnblogs.com/yupeng/p/3414736.html#commentform

class graph():
    def __init__(self,*arg,**kwargs):
        self.node_neighbors={}
        self.visited={}

    def add_nodes(self,nodelist):
        for node in nodelist:
            self.add_node(node)

    def add_node(self,node):
        if node not in self.node_neighbors.keys:
            self.node_neighbors[node]=[]

    def add_edge(self,edge):
        u,v=edge
        if (u not in self.node_neighbors[v]) and (v not in self.node_neighbors[u]):
            self.node_neighbors[u].append(v)
            if u!=v:
                self.node_neighbors[v].append(u)

    def depth_first_search(self,root=None):
        self.visited={}
        order=[]
        def dfs(n):
            self.visited[n]=True
            order.append(n)
            for node in self.node_neighbors[n]:
                if node not in self.visited:
                    dps(node)
        if root:
            dps(root)
        for n in self.node_neighbors.keys:
            if n not in self.visited:
                dps(n)
        print(order)
        return order

    def breadth_first_search(self,root=None):
        self.visited={}
        order=[]
        queue=[]
        def bfs():
            while(len(queue)>0):
                node = queue.pop(0)
                self.visited[node]=True
                for n in self.node_neighbors[node]:
                    if not n in self.visited and not n in queue:
                        order.append(n)
                        queue.append(n)


        if root:
            queue.append(root)
            order.append(root)
            bfs()

        for node in self.nodes():
            if not node in self.visited:
                queue.append(node)
                order.append(node)
                bfs()
        print (order)

        return order

if __name__ == '__main__':
    g = Graph()
g.add_nodes([i+1 for i in range(8)])
g.add_edge((1, 2))
g.add_edge((1, 3))
g.add_edge((2, 4))
g.add_edge((2, 5))
g.add_edge((4, 8))
g.add_edge((5, 8))
g.add_edge((3, 6))
g.add_edge((3, 7))
g.add_edge((6, 7))
print ("nodes:", g.node_neighbors)

order = g.breadth_first_search(1)
order = g.depth_first_search(1)