[C] - 二叉排序树

来源：网络

  
    

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


   
     struct
   
      nodb
{
 
   
     int
   
      data;
 
   
     struct
   
      nodb 
   
     *
   
     lch,
   
     *
   
     rch;
};

   
     struct
   
      nodb 
   
     *
   
     root,
   
     *
   
     q,
   
     *
   
     p;


   
     void
   
      insert1(
   
     struct
   
      nodb 
   
     *
   
     s);


   
     void
   
      creat()
{
 
   
     struct
   
      nodb 
   
     *
   
     s;
 
   
     int
   
      i,n,k;
 printf(
   
     "
   
     n=?
   
     "
   
     );
 scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     n);
 
 
   
     for
   
     (i
   
     =
   
     1
   
     ;i
   
     <
   
     n;i
   
     ++
   
     )
 {
 printf(
   
     "
   
     k%d=?
   
     "
   
     ,i);
 scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     k);
 s
   
     =
   
     (
   
     struct
   
      nodb 
   
     *
   
     )malloc(
   
     sizeof
   
     (
   
     struct
   
      nodb));
 s
   
     ->
   
     data
   
     =
   
     k;s
   
     ->
   
     lch
   
     =
   
     NULL;s
   
     ->
   
     rch
   
     =
   
     NULL;
 insert1(s);
 }
}



   
     void
   
      insert1(
   
     struct
   
      nodb 
   
     *
   
     s)
{ 
   
     //
   
     非递归插入
   
     

   
      
   
     struct
   
      nodb 
   
     *
   
     p,
   
     *
   
     q;
 
   
     if
   
     (root
   
     ==
   
     NULL)
 root
   
     =
   
     s;
 
   
     else
   
     
 {
 p
   
     =
   
     root;
 
   
     while
   
     (p
   
     !=
   
     NULL)
 {
 q
   
     =
   
     p;
   
     //
   
     当p向子数节点移动时，q记录p的双亲的位置
   
     

   
      
   
     if
   
     (s
   
     ->
   
     data
   
     <
   
     p
   
     ->
   
     data)
 p
   
     =
   
     p
   
     ->
   
     lch;
 
   
     else
   
     
 p
   
     =
   
     p
   
     ->
   
     rch;
 }
 
   
     if
   
     (s
   
     ->
   
     data
   
     <
   
     q
   
     ->
   
     data)
 q
   
     ->
   
     lch
   
     =
   
     s;
 
   
     else
   
      
 q
   
     ->
   
     rch
   
     =
   
     s;
   
     //
   
     当p为空时，q就是可插入的地方
   
     

   
      }
}


   
     void
   
      print(
   
     struct
   
      nodb 
   
     *
   
     t)
{
 
   
     if
   
     (t
   
     !=
   
     NULL)
 {
 print(t
   
     ->
   
     lch);
 printf(
   
     "
   
     %6d
   
     "
   
     ,t
   
     ->
   
     data);
 print(t
   
     ->
   
     rch);
 }
}


   
     void
   
      bstsrch(
   
     struct
   
      nodb
   
     *
   
     t,
   
     int
   
      k)
{
 
   
     int
   
      flag;
 p
   
     =
   
     NULL;
 q
   
     =
   
     t;
 flag
   
     =
   
     0
   
     ;
 
   
     while
   
     ((q
   
     !=
   
     NULL)
   
     &&
   
     (flag
   
     ==
   
     0
   
     ))
 {
 
   
     if
   
     (q
   
     ->
   
     data
   
     ==
   
     k)
 {
 printf(
   
     "
   
     发现 %5d
   
     "
   
     ,q
   
     ->
   
     data);
 flag
   
     =
   
     1
   
     ;
 }
 
   
     else
   
      
   
     if
   
     (k
   
     <
   
     q
   
     ->
   
     data)
 {
 p
   
     =
   
     q;
 q
   
     =
   
     q
   
     ->
   
     lch;
 }
 
   
     else
   
     
 {
 p
   
     =
   
     q;
 q
   
     =
   
     q
   
     ->
   
     rch;
 }
 }
 
   
     if
   
     (flag
   
     ==
   
     0
   
     )printf(
   
     "
   
     没有发现节点
   
     "
   
     );
}


   
     void
   
      bstins(
   
     struct
   
      nodb 
   
     *
   
     t,
   
     int
   
      k)
{
 
   
     struct
   
      nodb 
   
     *
   
     r;
 bstsrch(root,k);
 
   
     if
   
     (q
   
     ==
   
     NULL)
 {
 r
   
     =
   
     (
   
     struct
   
      nodb
   
     *
   
     )malloc(
   
     sizeof
   
     (
   
     struct
   
      nodb));
 r
   
     ->
   
     data
   
     =
   
     k;
 r
   
     ->
   
     lch
   
     =
   
     NULL;
 r
   
     ->
   
     rch
   
     =
   
     NULL;
 
   
     if
   
     (root
   
     ==
   
     NULL)
 root
   
     =
   
     r;
 
   
     else
   
      
   
     if
   
     (k
   
     <
   
     p
   
     ->
   
     data)
 p
   
     ->
   
     lch
   
     =
   
     r;
 
   
     else
   
     
 p
   
     ->
   
     rch
   
     =
   
     r;
 }
}

main()
{
 
   
     int
   
      n;
 root
   
     =
   
     0
   
     ;
 creat();
 print(root);
 printf(
   
     "
   
     请出入关键值n=?
   
     "
   
     );
 scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     n);
 bstsrch(root,n);
 printf(
   
     "
   
     \n
   
     "
   
     );
 bstins(root,n);
 print(root);
}