此篇记录下数据结构图的实现，带权重的无向图，邻接矩阵表示边集合，为接下来的最小生成树做好准备。

class Graph(object):
    def __init__(self, maps):
        self.maps = maps
        self.nodenum = self.get_nodenum()
        self.edgenum = self.get_edgenum()

    def get_nodenum(self):
        return len(self.maps)

    def get_edgenum(self):
        count = 0
        for i in range(self.nodenum):
            for j in range(i):
                if self.maps[i][j] > 0:
                    count += 1
        return count

    def insert_node(self):
        for i in range(len(self.maps)):
            self.maps[i].append(-1)
        self.maps.append([-1]*(self.nodenum) + [0])
        self.nodenum += 1

    def insert_edge(self, x, y, weight):
        if x < 0 or x >= self.nodenum or y < 0 or y > self.nodenum or weight <= 0 or x == y:
            return
        else:
            self.maps[x][y] = self.maps[y][x] = weight
            self.edgenum += 1

    def breath_first_search(self):
        queue = []
        visited = [False]*self.nodenum
        res = []
        def bfs():
            while len(queue) > 0:
                i = queue.pop(0)
                for j in range(self.nodenum):
                    if self.maps[i][j] > 0 and visited[j] == False:
                        res.append(j)
                        visited[j] = True
                        queue.append(j)

        if self.nodenum <= 0:
            return res
        else:
            queue.append(0)#index, value
            visited[0] = True
            res.append(0)
            bfs()
        
        for i in range(self.nodenum):
            if visited[i] == False:
                res.append(i)
                visited[i] = True
                queue.append(i)
                bfs()
        
        return res

    def depth_first_search(self):
        res = []
        visited = [False]*self.nodenum
        def dfs(i):
            res.append(i)
            visited[i] = True
            for j in range(self.nodenum):
                if self.maps[i][j] > 0 and visited[j] == False:
                    dfs(j)
        if self.nodenum > 0:
            dfs(0)
        for i in range(self.nodenum):
            if visited[i] == False:
                dfs(i)
        return res

maps = [[0,3,9,-1], [3,0,-1,5], [9,-1,0,-1], [-1,5,-1,0]]
graph = Graph(maps)
print('邻接矩阵为\n%s'%graph.maps)
print('节点数据为%d，边数为%d\n'%(graph.nodenum, graph.edgenum))
graph.insert_node()
print('-------插入一个节点--------')
print('邻接矩阵为%s'%graph.maps)
print('节点数据为%d，边数为%d\n'%(graph.nodenum, graph.edgenum))
graph.insert_edge(0, 4, 7)
print('-------插入一个边--------')
print('邻接矩阵为%s'%graph.maps)
print('节点数据为%d，边数为%d\n'%(graph.nodenum, graph.edgenum))
print('-------广度优先遍历--------')
print(graph.breath_first_search())
print('-------深度优先遍历--------')
print(graph.depth_first_search())

初始化的图如下。

插入一个节点与边后如下。

运行结果如下。