java 中怎么存储图的

    //演示程序:邻接矩阵表示的带权有向图（网）import java.io.*;    //最大边数和顶点数// “邻接矩阵”类class Graph {        static int MaxEdges = 50;        static int MaxVertices = 10;    static double MaxValue=9999.9;  //无穷大        //存放顶点的数组    private char VerticesList[]=new char[MaxVertices];    //邻接矩阵（存放两个顶点权值）    private double Edge[][]=new double[MaxVertices][MaxVertices];    private int CurrentEdges; //现有边数    private int CurrentVertices; //现有顶点数    //构造函数：建立空的邻接矩阵    public Graph ( ){        for ( int i = 0; i < MaxVertices; i++ )                for ( int j = 0; j < MaxVertices; j++ )                 if(i==j)                    Edge[i][j] = 0; //对角线                else    //非对角线上无穷大                    Edge[i][j] =MaxValue;         CurrentEdges = 0;  //现有边数        CurrentVertices = 0;  //现有顶点数    }    //查找指定的顶点的序号    public int FindVertex (char vertex){        //在顶点数组里面查找        for(int i=0;i<CurrentVertices;i++)            if(VerticesList[i]==vertex)                 return i; //返回下标        return -1;  //没有找到    }    //图空否？    public boolean IsGraphEmpty ( ){         return CurrentVertices==0;     }    //图满否？    public boolean IsGraphFull ( ){         return CurrentVertices==MaxVertices ||            CurrentEdges==MaxEdges;     }    //取得顶点数    public int NumberOfVertices ( ){         return CurrentVertices;     }    //取得边数    public int NumberOfEdges ( ){         return CurrentEdges;     }    //按序号取得顶点值    public char GetValue ( int i ){         return i >= 0 && i <= CurrentVertices-1                   ? VerticesList[i] : ' ';       }      //取得一条边的权值    public double GetWeight ( int v1,  int v2 ){        if (v1 < 0 || v1 > CurrentVertices - 1)             return -1.0; //用-1表示出错        if (v2 < 0 || v2 > CurrentVertices - 1)             return -1.0;        return Edge[v1][v2];        }    //取得第一个邻接点的序号    public int GetFirstNeighbor ( int v ){        if (v< 0 || v > CurrentVertices - 1)                return -1;  //用-1表示出错    //邻接矩阵的行号和列号是两个邻接点的序号        for ( int col = 0; col < CurrentVertices; col++ )            if ( Edge[v][col] > 0 &&  //自身                Edge[v][col] < MaxValue ) //无穷大                return col;        return -1; //无邻接点    }    //插入一个顶点    public int InsertVertex ( char vertex ){        if(IsGraphFull()) return -1;  //插入失败        //顶点表增加一个元素        VerticesList[CurrentVertices]=vertex;        //邻接矩阵增加一行一列        for ( int j = 0;j <=CurrentVertices;j++ ) {                    Edge[CurrentEdges][j]=MaxValue;            Edge[j][CurrentEdges]=MaxValue;        }        Edge[CurrentEdges][CurrentEdges]=0;        CurrentVertices++;        return CurrentVertices;  //插入位置    }    //插入一个边    public boolean InsertEdge( int v1,  int v2, double weight){        if (v1 < 0 || v1 > CurrentVertices - 1)             return false; //出错        if (v2 < 0 || v2 > CurrentVertices - 1)             return false;        Edge[v1][v2]=weight; //网,有向边        return true;    }    //删除一个顶点    public boolean RemoveVertex ( int v ){        if (v< 0 || v > CurrentVertices - 1)                return false;  //出错        //修改顶点表        for(int i=v+1;i< CurrentVertices;i++)            VerticesList[i-1]=VerticesList[i];        //修改邻接矩阵        int k=0;  //累计将要删去的边数        for(int i=0;i< CurrentVertices;i++)            if ( Edge[v][i] > 0 &&  //自身                Edge[v][i] < MaxValue ) //无穷大                k++;  //第v行        for(int i=0;i< CurrentVertices;i++)            if ( Edge[i][v] > 0 &&  //自身                Edge[i][v] < MaxValue ) //无穷大                k++; //第v列        //覆盖第v行        int j;        for(int i=v+1;i< CurrentVertices;i++)            for(j=0;j< CurrentVertices;j++)                Edge[i-1][j]=Edge[i][j];        //覆盖第v列        for(j=v+1;j< CurrentVertices;j++)            for(int i=0;i< CurrentVertices;i++)                Edge[i][j-1]=Edge[i][j];        CurrentVertices--; //修改顶点数        CurrentEdges-=k;  //修改边数        return true;    }    //删除一个边    public boolean RemoveEdge ( int v1,  int v2 ){        if (v1 < 0 || v1 > CurrentVertices - 1)             return false; //用-1表示出错        if (v2 < 0 || v2 > CurrentVertices - 1)             return false;        if ( v1==v2) return false;        Edge[v1][v2]=MaxValue; //网,无路径        return true;    }    //打印邻接矩阵    public void display(){        int i,j;        System.out.println("  顶点表");        for(i=0;i<CurrentVertices;i++)            System.out.print(VerticesList[i]+" ");        System.out.println('\n'+"  邻接矩阵");        for(i=0;i<CurrentVertices;i++) {            for(j=0;j<CurrentVertices;j++)                if(Edge[i][j]==MaxValue)                    System.out.print('@'+" ");                else                    System.out.print(Edge[i][j]+" ");            System.out.println();        }    }    //主函数    public static void main(String []args){            Graph G=new Graph(); //邻接矩阵        //准备有向图（网）数据        char c[]={'A','B','C','D','E','F'}; //顶点            int v[][]={  //弧            {0,1},{0,3},{1,2},{2,3},{4,5},            {1,3},{2,4},{3,5},{4,3},{2,5}        };            double e[]={2.3,3.6,6.5,2.5,1.7,            0.8,7.2,9.1,5.2,1.3}; //权                //插入顶点        for(int i=0;i<6;i++)             G.InsertVertex(c[i]);        //插入弧        for(int i=0;i<10;i++)            G.InsertEdge(v[i][0],v[i][1],e[i]);        //打印输出        G.display();        //删除一个顶点        G.RemoveVertex(3);        G.display();        //删除一条边        G.RemoveEdge(2,4);        G.display();        } //main方法结束}  //“邻接矩阵”类结束