btree with C

btree.c

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

struct Node
{
    int Val;
    struct Node *left;
    struct Node *right;
};

struct Node* newNode() 
{
    struct Node* n;
    n = (struct Node*)malloc(sizeof(struct Node));

    n->right = 0x0;
    n->left = 0x0;

    return n;
}

struct Node* insert(struct Node* root,int val)
{
    if (root == NULL) {
        struct Node* n;
        n = newNode();
        n->Val = val;

        return n;
    }
    if (val < root->Val) {
        root->left = insert(root->left,val);
    } else if (val > root->Val) {
        root->right = insert(root->right,val);
    }
    
    return root;
}

void inoder(struct Node* root)
{
    if (root) {
       inoder(root->left);
       printf("%d ",root->Val);
       inoder(root->right);
    }
}

struct Node* max_node(struct Node* root)
{
    if (!root->right) {
        return root;
    }
    
    return max_node(root->right);
}

struct Node* delete_node(struct Node* root,int val)
{
    if (root == NULL) {
        return NULL;
    }
    if (val < root->Val) {
        root->left = delete_node(root->left,val);
    }
    else if (val > root->Val) {
        root->right = delete_node(root->right,val);
    }
    else
    {
        if (root->left == NULL) {
            root = root->right;
        } else if (root->right == NULL)
        {
            root = root->left;
        } else
        {
            struct Node* d;
            d = max_node(root->left);
            root->Val = d->Val;
            root->left = delete_node(root->left,d->Val);
            free(d);
        }
    }
    
    return root;
}

/*
output:
2 5 10 13 15 16 40
2 5 10 13 15 16
2 10 13 15 16
max:16
*/
int main(void)
{
    struct Node *root;
    root = newNode();
    root->Val = 10;
    root = insert(root,5);
    root = insert(root,15);
    root = insert(root,16);
    root = insert(root,13);
    root = insert(root,2);
    root = insert(root,40);
    inoder(root);
    printf("\n");

    root = delete_node(root,40);
    inoder(root);
    printf("\n");

    root = delete_node(root,5);
    inoder(root);
    printf("\n");

    struct Node *maxNode;
    maxNode = max_node(root);
    printf("max:%d\n",maxNode->Val);

    getchar();

    return 0;
}