深度优先搜索算法

#include <stdio.h>
#include<stdlib.h>

struct node 
{
 int vertex ;
 struct node *link ;
};

#define  TRUE 1
#define  FALSE 0
typedef struct node *graph ;
struct node head [ 9 ] ;
int visited [ 9 ] ;

void CreateGraph( int *node , int num  )
{
 graph ptr ;
 graph newnode ;
 int from ;
 int to , i ;
 for ( i = 0 ; i < num ; i++)
 {
  from = node[ i * 2] ;
  to = node [ i * 2 +1 ] ;
  newnode = (graph)malloc(sizeof(struct node));
  newnode ->vertex = to ;
  newnode ->link = NULL ;
  ptr = &(head [ from ]);

  while ( ptr -> link != NULL )
  {
   ptr = ptr ->link ;
  }
  ptr->link = newnode ;
 }

}

void DFS( int v)
{
 graph ptr ;
 visited[ v ] = TRUE ;
 printf( " v%d " ,v ) ;
 ptr = head[ v ].link ;
 while( ptr != NULL )
 {
  if ( visited[ ptr->vertex ] == FALSE )
  {
   DFS( ptr->vertex ) ;
  }
  ptr = ptr ->link ;
 }
}

void main()
{
 int node[20][2]=  { {1, 2}, {2, 1}, 
 {1, 3}, {3, 1},
 {2, 4}, {4, 2},
 {2, 5}, {5, 2},
 {3, 6}, {6, 3},
 {3, 7}, {7, 3},
 {4, 8}, {8, 4},
 {5, 8}, {8, 5},
 {6, 8}, {8, 6},
 {7, 8}, {8, 7} };

 CreateGraph( node , 20 ) ;
 puts("图的深度遍历结果：") ;
 DFS( 3 ) ;
 puts( " " );

 

}