Binary Search Tree C implementation OII

#include <stdio.h>

/**
    Defining a node
**/
struct node {
    char data;
    struct node *left;
    struct node *right;
};

typedef struct node Node;

/// Tree construction
Node* new_node ( char );

/*** BST only functions **/
Node* search ( Node*, char );

Node* insert ( Node*, char );
/**
    Dept first search
**/
/// Dept first search in order
void dfs_in_order ( Node* );

/// Dept first search pre order
void dfs_pre_order ( Node* );

/// Dept first search post order
void dfs_post_order ( Node* );

int main ( void )
{
    Node *root = new_node( 'H' );

    insert ( root, 'B' );
    insert ( root, 'Z' );
    insert ( root, 'D' );
    insert ( root, 'F' );
    insert ( root, 'C' );

    printf ( "DFS Pre order: \n" );
    dfs_pre_order( root );

    printf ( "\nDFS In order: \n" );
    dfs_in_order( root );

    printf ( "\nDFS Post order: \n" );
    dfs_post_order( root );

    return 0;
}

Node* search ( Node* tree, char data ) {
    if ( tree == NULL || tree->data == data )
        return tree;

    if ( data > tree->data )
        return search ( tree->right, data );

    return search ( tree->left, data );
}

Node* new_node ( char data ) {
    Node *new_node = ( Node* ) malloc ( sizeof ( Node ) );

    new_node->data = data;
    new_node->left = NULL;
    new_node->right = NULL;

    return new_node;
}

Node* insert ( Node* tree, char data ) {
    if ( tree == NULL ) return new_node( data );

    if ( tree->data < data )
        tree->left = insert ( tree->left, data );

    if ( tree->data > data )
        tree->right = insert ( tree->right, data );

    return tree;
}

void dfs_in_order ( Node *tree ) {
    /// Root
    if ( tree == NULL )
        return;

    /// Left subtree
    dfs_in_order( tree->left );

    printf ( "%c ", tree->data );

    /// Right subtree
    dfs_in_order( tree->right );
}

void dfs_pre_order ( Node *tree ) {
    /// Root
    if ( tree == NULL )
        return;

    printf ( "%c ", tree->data );

    /// Left subtree
    dfs_pre_order( tree->left );

    /// Right subtree
    dfs_pre_order( tree->right );
}

void dfs_post_order ( Node *tree ) {
    /// Root
    if ( tree == NULL )
        return;

    /// Left subtree
    dfs_post_order( tree->left );

    /// Right subtree
    dfs_post_order( tree->right );

    printf ( "%c ", tree->data );
}