C / C++ / MFC

<br />
#include <stdio.h><br />
#include <stdlib.h><br />
<br />
struct tree_node{<br />
      int data;<br />
      struct tree_node *left_p, *right_p;<br />
};<br />
<br />
/*<br />
* Tree search algorithm.<br />
* Searches for value 'v' in tree,<br />
* returns pointer to first node found containing<br />
* the value otherwise 0.<br />
*/<br />
struct tree_node *<br />
t_search(struct tree_node *root, int v){<br />
<br />
      while(root){<br />
              printf("looking for %d, looking at %d\n",<br />
                      v, root->data);<br />
              if(root->data == v)<br />
                      return(root);<br />
              if(root->data > v)<br />
                      root = root->left_p;<br />
              else<br />
                      root = root->right_p;<br />
      }<br />
      /* value not found, no tree left */<br />
      return(0);<br />
}<br />
/*<br />
* Insert node into tree.<br />
* Return 0 for success,<br />
* 1 for value already in tree,<br />
* 2 for malloc error<br />
*/<br />
int<br />
t_insert(struct tree_node **root, int v){<br />
<br />
      while(*root){<br />
              if((*root)->data == v)<br />
                      return(1);<br />
              if((*root)->data > v)<br />
                      root = &((*root)->left_p);<br />
              else<br />
                      root = &((*root)->right_p);<br />
      }<br />
      /* value not found, no tree left */<br />
      if((*root = (struct tree_node *)<br />
              malloc(sizeof (struct tree_node)))<br />
                      == 0)<br />
              return(2);<br />
      (*root)->&data = v;<br />
      (*root)->&left_p = 0;<br />
      (*root)->&right_p = 0;<br />
      return(0);<br />
}<br />
<br />
main(){<br />
      /* construct tree by hand */<br />
      struct tree_node *tp, *root_p = 0;<br />
      int i;<br />
<br />
      /* we ingore the return value of t_insert */<br />
      t_insert(&root_p, 4);<br />
      t_insert(&root_p, 2);<br />
      t_insert(&root_p, 6);<br />
      t_insert(&root_p, 1);<br />
      t_insert(&root_p, 3);<br />
      t_insert(&root_p, 5);<br />
      t_insert(&root_p, 7);<br />
<br />
      /* try the search */<br />
      for(i = 1; i < 9; i++){<br />
              tp = t_search(root_p, i);<br />
              if(tp)<br />
                      printf("%d found\n", i);<br />
              else<br />
                      printf("%d not found\n", i);<br />
      }<br />
      exit(EXIT_SUCCESS);<br />
}<br />