typedef struct node
{
    unsigned int key;
    struct node *left;
    struct node *right;
} node ;

void addNode(node **tree, unsigned int key)
{
    node *tmpNode;
    node *tmpTree = *tree;

    node *elem = malloc(sizeof(node));
    elem->key = key;
    elem->left = NULL;
    elem->right = NULL;

    if(tmpTree)
    do
    {
        tmpNode = tmpTree;
        if(key > tmpTree->key )
        {
            tmpTree = tmpTree->right;
            if(!tmpTree) tmpNode->right = elem;
        }
        else
        {
            tmpTree = tmpTree->left;
            if(!tmpTree) tmpNode->left = elem;
        }
    }
    while(tmpTree);
    else  *tree = elem;
}

    node *Arbre = NULL;
	//...
    addNode(&Arbre, 30);


int searchNode(node *tree, unsigned int key)
{
    while(tree)
    {
        if(key == tree->key) return 1;

        if(key > tree->key ) tree = tree->right;
        else tree = tree->left;
    }
    return 0;
}



    if(searchNode(Arbre, Key)) //...


void printTree(node *tree)
{
    if(!tree) return;

    if(tree->left)  printTree(tree->left);

    printf("Cle = %d\n", tree->key);

    if(tree->right) printTree(tree->right);
}


void printReverseTree(node *tree)
{
    if(!tree) return;

    if(tree->right) printReverseTree(tree->right);

    printf("Cle = %d\n", tree->key);

    if(tree->left)  printReverseTree(tree->left);
}


void clearTree(node **tree)
{
    node *tmpTree = *tree;

    if(!tree) return;

    if(tmpTree->left)  clearTree(&tmpTree->left);

    if(tmpTree->right) clearTree(&tmpTree->right);

    free(tmpTree);	

    *tree = NULL;
}