binary tree (numbers+) [working]

#include <stdio.h>
#include <stdlib.h>

typedef struct _node {
    int data;
    struct _node *right, *left;
} node;


node *addNode(node *head, int num)
{
    node *el = (node*) malloc(sizeof(node));
    el->left = NULL;
    el->right = NULL;
    el->data = num;
    if (!head)
        return el;
    if (head->data > num) head->left = addNode(head->left, num);
    else head->right = addNode(head->right, num);
    return head;
}

//print tree in line
void reprint(node *head)
{
    if (!head) return;
    reprint(head->left);
    printf("%d ", head->data);
    reprint(head->right);
}

//get height of tree
int height(node *head)
{
    int hl, hr;
    if (!head) return 0;
    hl = height(head->left) + 1;
    hr = height(head->right) + 1;

    return hl > hr ? hl : hr;
}

//structured print of tree
void print(node *head, int level, int curr)
{
    if (!head) return;
    print(head->left, level, curr+1);
    if (level == curr) printf("%d\t", head->data);
    else putchar('\t');
    print(head->right, level, curr+1);
}

void printn(node *head)
{
    int h, i = 0;
    if(!head) return;
    h = height(head);

    while(i <= h)
    {
        print(head, i++, 0);
        printf("\n");
    }
}
//end - structured print of tree

int main()
{
    int n;
    node *head = NULL;
    printf("input tree: ");
    while (1)
    {
        scanf("%d", &n);
        if (!n) break;
        head = addNode(head, n);
    }
    printn(head);
    printf("\n%d\n", height(head));
    _getch();
    return 0;
}