Linked Representation of Binary Tree

struct node {
int data;
struct node* left;
struct node* right;
};
struct node* CreateNode(int data){
struct node *n;
n = (struct node*)malloc(sizeof(struct node);
n->data = data;
n->left = NULL;
n->right = NULL;
return n;
}
struct node *p = createNode(2);
struct node *p1 = createNode(1);
struct node *p2 = createNode(4);

    // Linking the root node with left and right children
    p->left = p1;
    p->right = p2;

PreOrder traversal in Binary Tree

// Constructing the root node - Using Function (Recommended)
    struct node *p = createNode(4);
    struct node *p1 = createNode(1);
    struct node *p2 = createNode(6);
    struct node *p3 = createNode(5);
    struct node *p4 = createNode(2);
    // Finally The tree looks like this:
    //      4
    //     / \\
    //    1   6
    //   / \\
    //  5   2  

    // Linking the root node with left and right children
    p->left = p1;
    p->right = p2;
    p1->left = p3;
    p1->right = p4;

void preOrder(struct  node* root){
    if(root!=NULL){
        printf("%d ", root->data);
        preOrder(root->left);
        preOrder(root->right);
    }
}

PostOrder traversal in binary tree

// Constructing the root node - Using Function (Recommended)
    struct node *p = createNode(4);
    struct node *p1 = createNode(1);
    struct node *p2 = createNode(6);
    struct node *p3 = createNode(5);
    struct node *p4 = createNode(2);
    // Finally The tree looks like this:
    //      4
    //     / \\
    //    1   6
    //   / \\
    //  5   2  

    // Linking the root node with left and right children
    p->left = p1;
    p->right = p2;
    p1->left = p3;
    p1->right = p4;

void postOrder(struct  node* root){
    if(root!=NULL){
        postOrder(root->left);
        postOrder(root->right);
        printf("%d ", root->data);
    }
}