有向图-邻接表方式

【lua实现】

local DGraph = {}
DGraph.__index = DGraph

function DGraph.new()
    local obj = {}
    setmetatable(obj, DGraph)

    obj:ctor()
    return obj
end

function DGraph:ctor()
    self.adjacent = {}
    self.edgeCount = 0
    self.vertexList = {}
end

function DGraph:GetVertexCount()
    return #self.vertexList
end

function DGraph:GetEdgeCount()
    return self.edgeCount
end

function DGraph:AddVertex(v)
    local list = self.adjacent[v]
    if nil == list then
        list = {}
        self.adjacent[v] = list
        table.insert(self.vertexList, v)
    else
        --顶点已存在
    end
end

function DGraph:AddEdge(v1, v2)
    local list1 = self.adjacent[v1]
    local list2 = self.adjacent[v2]
    if nil == list1 or nil == list2 then
        return --顶点不存在
    end
    table.insert(list1, v2)
    self.edgeCount = self.edgeCount + 1
end

function Graph:GetAdjacent(v)
    return self.adjacent[v]
end

function DGraph:__tostring()
    print("-----DGraph")
    for i=1,#self.vertexList do
        local v = self.vertexList[i]
        local adjList = self.adjacent[v]
        print(v, "-->", table.concat(adjList, ", "))
    end
    print("-----")
end

 

测试代码：

function CreateDGraph()
    local g = DGraph.new()
    g:AddVertex("0")
    g:AddVertex("1")
    g:AddVertex("2")
    g:AddVertex("3")
    g:AddVertex("4")
    g:AddVertex("5")

    g:AddEdge("0", "2")
    g:AddEdge("2", "0")
    g:AddEdge("2", "1")
    g:AddEdge("2", "3")
    g:AddEdge("3", "2")
    g:AddEdge("3", "4")
    g:AddEdge("3", "5")

    print(g:GetEdgeCount())
    print(g:GetVertexCount())
    tostring(g)
end
CreateDGraph()

 

【参考】

 图论算法——有向图的邻接链表实现_日积月累，天道酬勤-CSDN博客_有向图邻接链表