图的邻接表

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#define MAX 100
struct ArcNode               //边节点 
{
       int adjvex;                      
       ArcNode *nextarc;
};
struct VNode
{
       int data;
       ArcNode *head1;      //入边的表头指针 
       ArcNode *head2;      //出边的表头指针 
};
struct LGraph
{
       VNode vertexs[MAX];          //顶点数组 
       int vexnum, arcnum;         //顶点数和边数 
};
LGraph lg;

void CreateLG()
{
     int i = 0;
     ArcNode *pi;
     int v1, v2;
     lg.vexnum = lg.arcnum = 0;
     scanf( "%d%d", &lg.vexnum, &lg.arcnum );
     for( i = 0; i < lg.vexnum; i++ )        //初始化 
          lg.vertexs[i].head1 = lg.vertexs[i].head2 = NULL;
     for( i = 0; i < lg.arcnum; i++ )                 //邻接表的插入 
     {
          scanf( "%d%d", &v1, &v2 );
          v1--; v2--;
          pi = (ArcNode *)malloc( sizeof(ArcNode) );
          pi->adjvex = v2;
          pi->nextarc = lg.vertexs[v1].head1;
          lg.vertexs[v1].head1 = pi;
          pi = (ArcNode *)malloc( sizeof(ArcNode) );
          pi->adjvex = v1;
          pi->nextarc = lg.vertexs[v2].head2;
          lg.vertexs[v2].head2 = pi;
     }
}
void DeleteLG()                  //删除邻接表 
{
     int i;
     ArcNode *pi;
     for( i = 0; i < lg.vexnum; i++ )
     {
          pi = lg.vertexs[i].head1;
          while( pi != NULL )
          {
                 lg.vertexs[i].head1 = pi->nextarc;
                 free( pi );
                 pi = lg.vertexs[i].head1;
          }
          pi = lg.vertexs[i].head2;
          while( pi != NULL )
          {
                 lg.vertexs[i].head2 = pi->nextarc;
                 free( pi );
                 pi = lg.vertexs[i].head2;
          }
     }
}
int main()          //主函数 
{
    int i;
    int id, od;
    ArcNode *pi;
    while( 1 )
    {
           lg.vexnum = lg.arcnum = 0;
           scanf( "%d%d", &lg.vexnum, &lg.arcnum );
           if( lg.vexnum == 0 )       break;
           CreateLG( );
           for( i = 0; i < lg.vexnum; i++ )
           {
                od = 0;
                pi = lg.vertexs[i].head1;
                while( pi != NULL )
                {
                       od++;
                       pi = pi->nextarc;
                }
                if( i == 0 ) printf( "%d", od );
                else printf( " %d", od );
           }
           printf( "\n" );
           for( i = 0; i < lg.vexnum; i++ )
           {
                id = 0;
                pi = lg.vertexs[i].head2;
                while( pi != NULL )
                {
                       id++;
                       pi = pi->nextarc;
                }
                if( i == 0 ) printf( "%d", id );
                else  printf( " %d", id );
           }
           printf( "\n" );
           DeleteLG();
    }
    return 0;
}