poj 2255 Tree Recovery

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 4024		Accepted: 2698

本题与杭电acm上的1710几乎上相同，而且比杭电上的更容易些，所以在这里就不罗嗦了，如果有兴趣可以看我的另一篇随笔，hdu 1710  Binary Tree Traversals

代码：

 

  
    

   
     
   
      1 
   
     #include
   
     <
   
     stdio.h
   
     >
   
     

   
      2 
   
     #include
   
     <
   
     stdlib.h
   
     >
   
     

   
      3 
   
     #include
   
     <
   
     string
   
     .h
   
     >
   
     

   
      4 
   
      
   
     int
   
      n;
   
     char
   
      pre[
   
     30
   
     ],
   
     in
   
     [
   
     30
   
     ];

   
      5 
   
     typedef 
   
     struct
   
      node

   
      6 
   
     {

   
      7 
   
      
   
     char
   
      data;

   
      8 
   
      
   
     int
   
      index;

   
      9 
   
      
   
     struct
   
      node 
   
     *
   
     Lchild,
   
     *
   
     Rchild;

   
     10 
   
     }bitree,
   
     *
   
     Tree;

   
     11 
   
      
   
     void
   
      dfs(Tree 
   
     &
   
     root,
   
     int
   
      index)

   
     12 
   
     {

   
     13 
   
      
   
     if
   
     (root
   
     ==
   
     NULL)

   
     14 
   
      {

   
     15 
   
      root
   
     =
   
     (Tree)malloc(
   
     sizeof
   
     (bitree));

   
     16 
   
      root
   
     ->
   
     data
   
     =
   
     in
   
     [index];

   
     17 
   
      root
   
     ->
   
     index
   
     =
   
     index;

   
     18 
   
      root
   
     ->
   
     Lchild
   
     =
   
     NULL;

   
     19 
   
      root
   
     ->
   
     Rchild
   
     =
   
     NULL;

   
     20 
   
      
   
     return
   
      ;

   
     21 
   
      }

   
     22 
   
      
   
     else
   
     

   
     23 
   
      {

   
     24 
   
      
   
     if
   
     (index
   
     <
   
     root
   
     ->
   
     index)

   
     25 
   
      dfs(root
   
     ->
   
     Lchild,index);

   
     26 
   
      
   
     else
   
     

   
     27 
   
      dfs(root
   
     ->
   
     Rchild,index);

   
     28 
   
      }

   
     29 
   
     }

   
     30 
   
      
   
     void
   
      createbitree(Tree 
   
     &
   
     root)

   
     31 
   
     {

   
     32 
   
      
   
     int
   
      i,j,index;

   
     33 
   
      root
   
     =
   
     (Tree)malloc(
   
     sizeof
   
     (bitree));

   
     34 
   
      
   
     for
   
     (i
   
     =
   
     0
   
     ;i
   
     <
   
     n;i
   
     ++
   
     )

   
     35 
   
      
   
     if
   
     (
   
     in
   
     [i]
   
     ==
   
     pre[
   
     0
   
     ])

   
     36 
   
      {

   
     37 
   
      root
   
     ->
   
     data
   
     =
   
     pre[
   
     0
   
     ];

   
     38 
   
      root
   
     ->
   
     index
   
     =
   
     i;

   
     39 
   
      root
   
     ->
   
     Lchild
   
     =
   
     NULL;

   
     40 
   
      root
   
     ->
   
     Rchild
   
     =
   
     NULL;

   
     41 
   
      
   
     break
   
     ;

   
     42 
   
      }

   
     43 
   
      index
   
     =
   
     i;

   
     44 
   
      
   
     for
   
     (i
   
     =
   
     1
   
     ;i
   
     <
   
     n;i
   
     ++
   
     )

   
     45 
   
      
   
     for
   
     (j
   
     =
   
     0
   
     ;j
   
     <
   
     n;j
   
     ++
   
     )

   
     46 
   
      
   
     if
   
     (
   
     in
   
     [j]
   
     ==
   
     pre[i])

   
     47 
   
      {

   
     48 
   
      
   
     if
   
     (j
   
     <
   
     index)

   
     49 
   
      dfs(root
   
     ->
   
     Lchild,j);

   
     50 
   
      
   
     else
   
     

   
     51 
   
      dfs(root
   
     ->
   
     Rchild,j);

   
     52 
   
      
   
     break
   
     ;

   
     53 
   
      }

   
     54 
   
     }

   
     55 
   
      
   
     void
   
      post(Tree root)

   
     56 
   
     {

   
     57 
   
      
   
     if
   
     (root
   
     ==
   
     NULL)

   
     58 
   
      
   
     return
   
      ;

   
     59 
   
      post(root
   
     ->
   
     Lchild);

   
     60 
   
      post(root
   
     ->
   
     Rchild);

   
     61 
   
      printf(
   
     "
   
     %c
   
     "
   
     ,root
   
     ->
   
     data);

   
     62 
   
     }

   
     63 
   
      
   
     int
   
      main()

   
     64 
   
     {

   
     65 
   
      
   
     int
   
      i;

   
     66 
   
      
   
     while
   
     (scanf(
   
     "
   
     %s%s
   
     "
   
     ,pre,
   
     in
   
     )
   
     !=
   
     EOF)

   
     67 
   
      {

   
     68 
   
      Tree root;

   
     69 
   
      n
   
     =
   
     strlen(pre);

   
     70 
   
      createbitree(root);

   
     71 
   
      post(root);

   
     72 
   
      printf(
   
     "
   
     \n
   
     "
   
     );

   
     73 
   
      }

   
     74 
   
      
   
     return
   
      
   
     0
   
     ;

   
     75 
   
     }

   
     76