加权无向图-邻接表方式

 【理论知识，可以参考这边】

加权无向图的数据结构

 

【lua实现】

local Edge = {}
Edge.__index = Edge

function Edge.new(v1, v2, w)
    local obj = {}
    setmetatable(obj, Edge)

    obj:ctor(v1, v2, w)
    return obj
end

function Edge:ctor(v1, v2, w)
    self.v1 = v1
    self.v2 = v2
    self.w = w
end

function Edge:GetV1()
    return self.v1
end

function Edge:GetV2()
    return self.v2
end

function Edge:GetOther(v)
    if self.v1 == v then
        return self.v2
    end
    if self.v2 == v then
        return self.v1
    end
    return nil --error
end

function Edge:GetWeight()
    return self.w
end

function Edge:__eq(b)
    if self.w ~= b.w then
        return false
    end
    if self.v1 == b.v1 and self.v2 == b.v2 then
        return true
    end
    if self.v1 == b.v2 and self.v2 == b.v1 then
        return true
    end
    return false
end

 

local WeightedGraph = {}
WeightedGraph.__index = WeightedGraph

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

    obj:ctor()
    return obj
end

function WeightedGraph:ctor()
    self.adjacent = {}
    self.vertexList = {}
    self.edgeList = {}
end

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

function WeightedGraph:GetVertex(index)
    return self.vertexList[index]
end

function WeightedGraph:GetEdgeCount()
    return #self.edgeList
end

function WeightedGraph:AddVertex(v)
    local list = self.adjacent[v]
    if nil == list then
        list = {}
        self.adjacent[v] = list
        table.insert(self.vertexList, v)
    end
end

function WeightedGraph:AddEdge(v1, v2, w)
    local list1 = self.adjacent[v1]
    local list2 = self.adjacent[v2]
    if nil == list1 or nil == list2 then
        return --顶点不存在
    end
    local edge = Edge.new(v1, v2, w)
    table.insert(list1, edge)
    table.insert(list2, Edge.new(v2, v1, w))

    local exists = false
    for i=1,#self.edgeList do
        if edge == self.edgeList[i] then
            break
        end
    end
    if not exists then
        table.insert(self.edgeList, edge)
    end
end

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

function WeightedGraph:GetEdges()
    local list = {}
    for i=1,#self.edgeList do
        table.insert(list, self.edgeList[i])
    end
    return list
end

function WeightedGraph:__tostring()
    print("-----WeightedGraph")
    for i=1,#self.vertexList do
        local v = self.vertexList[i]
        local list = self.adjacent[v]
        local strBuilder = {}
        for j=1,#list do
            local edge = list[j]
            if j > 1 then
                table.insert(strBuilder, ",")
            end
            table.insert(strBuilder, "(")
            table.insert(strBuilder, edge:GetOther(v))
            table.insert(strBuilder, ":")
            table.insert(strBuilder, edge:GetWeight())
            table.insert(strBuilder, ")")
        end
        print(v, "->", table.concat(strBuilder))
    end
    print("-----")
end

 

测试代码：

function CreateGraph()
    local g = WeightedGraph.new()
    g:AddVertex("0")
    g:AddVertex("1")
    g:AddVertex("2")
    g:AddVertex("3")
    g:AddVertex("4")
    g:AddVertex("5")
    g:AddVertex("6")
    g:AddVertex("7")

    g:AddEdge("1", "3", 0.29)
    g:AddEdge("1", "5", 0.32)
    g:AddEdge("1", "7", 0.19)
    g:AddEdge("1", "2", 0.36)
    g:AddEdge("5", "4", 0.35)
    g:AddEdge("5", "7", 0.28)
    g:AddEdge("7", "0", 0.16)
    g:AddEdge("7", "2", 0.34)
    g:AddEdge("4", "0", 0.38)
    g:AddEdge("4", "6", 0.93)
    g:AddEdge("0", "6", 0.58)
    g:AddEdge("0", "2", 0.26)
    g:AddEdge("2", "6", 0.4)
    g:AddEdge("2", "3", 0.17)
    g:AddEdge("3", "6", 0.52)

    print("v ct: ", g:GetVertexCount())
    print("edge ct:", g:GetEdgeCount())
    tostring(g)
    return g
end
CreateGraph()

 

得到下面这样一张图：