校园导游图的课程设计(一)

思路：

1.  使用两个文件 arc 和 vex 分别存放 节点和弧信息

 存放格式为：

typedef struct data{
char placename[NAMEMAX];
char placedata[DATAMAX];
}Data;
typedef struct arc{
int forvex;
int backves;
int weight;
}Arc;//文件存储结构体

2. 为了方便删除和添加，使用邻接表，邻接表的结构体

typedef struct arcnode{
        int adjvex;
        int weight;
        struct arcnode* next;
}ArcNode;

typedef struct vertexnode{
        Data vexdata;
        ArcNode * next;
}VertxNode;

typedef struct {
        VertxNode vertex[NUMMAX];
        int vexnum;
        int arcnum;
}ListMatrix;

3. 为了方便操做和模块化，将地图的节点和弧的添加分别抽象成模块

int  AddArc( ListMatrix * G  )
/*
 * 增加弧
 * 成功返回1
 * 失败返回0
 */
{
     char forvextemp[NAMEMAX]; 
     char backvextemp[NAMEMAX];
     int forvex;
     int backvex;
     ArcNode * temp;
     ArcNode * p;
     printf("输入起始点:");
     scanf("%s",forvextemp);
    if( (forvex = NametoNum( G, forvextemp )) == 0  )
    {
            return 0;
    }
    printf("输入终点:");
    scanf("%s",backvextemp);
    if( (backvex = NametoNum( G,backvextemp)) == 0 )
    {
            return 0;
    }//读取起点和终点

    G->arcnum++;//弧数加一

    temp = (ArcNode*)malloc(sizeof(ArcNode));
    printf("输入路径长度:");
    scanf("%d",&temp->weight);
    temp->adjvex = backvex;
    temp->next = NULL;//赋值

    p = G->vertex[forvex].next;
    while( p&&p->next )  p = p->next;
    if( !p )  G->vertex[forvex].next = p;
    else      p->next = temp; //挂链
    return 1;
}

4.整个程序，只有在开始时读 arc vex 文件，建立map,在退出时写文件，将可能被修改过的map,覆盖写入 arc vex 文件

     其他所有操作都建立在内存中的map,不再对文件进行操作

int  MakeMap( ListMatrix *G )
/*
 * 利用文件建立地图
 * 输入存放节点的文件 fp1 ，存放弧的文件fp2
 *
*/
{ 
        FILE  * fp1;
        FILE  * fp2;
   int  nodecount = 0;
   int  arccount = 0;
   Data nodedata;
   Arc  arcdata;
   ArcNode * p;
   ArcNode * temp;
        if( (fp1=fopen("vex","ab+")) == NULL )
        {
             printf("vex打开错误");
             return 0;
        }
        if( (fp2=fopen("arc","ab+")) == NULL )
        {
                printf("arc打开错误
");
                return 0;
        }
   
   while( fread(&nodedata,sizeof(Data),1,fp1) == 1 )
   { 
           nodecount++; 
           strcpy(G->vertex[nodecount].vexdata.placename,nodedata.placename);
           strcpy(G->vertex[nodecount].vexdata.placedata,nodedata.placedata);  
           G->vertex[nodecount].next = NULL;
   }//读取节点

   if( nodecount != 0 )
   {
        while( fread( &arcdata,sizeof(Arc),1,fp2) == 1 )
        {
                arccount++;

                temp->next = ( ArcNode *)malloc(sizeof(ArcNode));
                temp->next->adjvex = arcdata.backves;
                temp->next->weight = arcdata.weight;
                temp->next->next = NULL;
 
                p = G->vertex[arcdata.forvex].next;
                while( p && p->next )  p = p->next;
                if( !p )    G->vertex[arcdata.forvex].next = temp;
                else        p->next =temp;//挂链
        }
   }//读取弧
   G->vexnum = nodecount;
   G->arcnum = arccount;
   fclose(fp1);
   fclose(fp2);
}