Change key bug in binary search tree

[fyra]

Hi people. I have a remove function that should set a hide member of a node to 1 instead of actually remove the node. The function works well when I insert and remove top and tap respectively (both nodes have their hide member set to 1) but when I insert and remove tap and top in this order, only top has its hidden member set to 1; tap is not found. I will attach a .zip since this program has some headers and sources.

int main(void)
{
   BiTree tree; 
   char* target;

   char sarray[12][STRSIZ];
   char tarray[12][STRSIZ];

    // load an array with the data to search
    strcpy(sarray[hop], "hop");
    strcpy(sarray[hat], "hat");
    strcpy(sarray[tap], "tap");
    strcpy(sarray[bat], "bat");
    strcpy(sarray[tip], "tip");
    strcpy(sarray[mop], "mop");
    strcpy(sarray[mom], "mom");
    strcpy(sarray[cat], "cat");
    strcpy(sarray[zoo], "zoo");
    strcpy(sarray[wax], "wax");
    strcpy(sarray[top], "top");
    strcpy(sarray[dip], "dip");

    // initialize the binary search tree
    bistree_init(&tree, compare_str, NULL);

    /* run some BST operations */

    printf("inserting some nodes\n");

    // insert a key into the tree
    if(bistree_insert(&tree, sarray[top]) != 0)
      return 1;  

    // print the size of the tree
    printf("tree size is %d\n", bistree_size(&tree));
    // traverse the tree in preorder
    printf("preorder traversal\n");
    preorder_tree(bitree_root(&tree));

    // insert a key into the tree
    if(bistree_insert(&tree, sarray[tap]) != 0)
      return 1;  

    // print the size of the tree
    printf("tree size is %d\n", bistree_size(&tree));
    // traverse the tree in preorder
    printf("preorder traversal\n");
    preorder_tree(bitree_root(&tree));

    // insert a key into the tree
    if(bistree_insert(&tree, sarray[cat]) != 0)
      return 1;

    // print the size of the tree
    printf("tree size is %d\n", bistree_size(&tree));
    // traverse the tree in preorder
    printf("preorder traversal\n");
    preorder_tree(bitree_root(&tree));

    // insert a key into the tree
    if(bistree_insert(&tree, sarray[bat]) != 0)
      return 1;

    // print the size of the tree
    printf("tree size is %d\n", bistree_size(&tree));
    // traverse the tree in preorder
    printf("preorder traversal\n");
    preorder_tree(bitree_root(&tree));

    // attempt remove a node from the tree
    printf("removing %s\n", sarray[tap]);
    // can't remove data from the tree
    if(bistree_remove(&tree, &sarray[tap]) != 0)
      printf("could not find %s\n", sarray[tap]);    
    // the key with its data was removed
    else 
    {
      // print the size of the tree
      printf("tree size is %d\n", bistree_size(&tree));
      // traverse the tree in preorder
      printf("preorder traversal\n");
      preorder_tree(bitree_root(&tree));
    }

    // attempt remove a node from the tree
    printf("removing %s\n", sarray[top]);
    // can't remove data from the tree
    if(bistree_remove(&tree, &sarray[top]) != 0)
      printf("could not find %s\n", sarray[top]);     
    // the key with its data was removed
    else    
    {
      // print the size of the tree
      printf("tree size is %d\n", bistree_size(&tree));
      // traverse the tree in preorder
      printf("preorder traversal\n");
      preorder_tree(bitree_root(&tree));
    }


    // lookup 
    printf("looking up some nodes\n");

    strcpy(tarray[0], "top");
    strcpy(tarray[1], "cat");
    strcpy(tarray[2], "wax");
    strcpy(tarray[3], "hat");
    strcpy(tarray[4], "xxx");

    target = tarray[0];
    // determine whether the data was found or not
    if(bistree_lookup(&tree, (void**)&target) != 0)
      printf("could not find %s\n", target);
    else 
      printf("Found %s\n", target);   

    target = tarray[2];
    // determine whether the data was found or not 
    if(bistree_lookup(&tree, (void**)&target) != 0)
      printf("could not find %s\n", target);
    else 
      printf("Found %s\n", target);

    // destroy the tree
    printf("Destroying the search tree\n");
    bistree_destroy(&tree);

    return EXIT_SUCCESS;
}