// C++ program for different tree traversals #include <iostream> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node *left, *right; }; //Utility function to create a new tree node Node* newNode(int data) { Node* temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } /* Given a binary tree, print its nodes according to the "bottom-up" postorder traversal. */ void printPostorder(struct Node* node) { if (node == NULL) return; // first recur on left subtree printPostorder(node->left); // then recur on right subtree printPostorder(node->right); // now deal with the node cout << node->data << " "; } /* Given a binary tree, print its nodes in inorder*/ void printInorder(struct Node* node) { if (node == NULL) return; /* first recur on left child */ printInorder(node->left); /* then print the data of node */ cout << node->data << " "; /* now recur on right child */ printInorder(node->right); } /* Given a binary tree, print its nodes in preorder*/ void printPreorder(struct Node* node) { if (node == NULL) return; /* first print data of node */ cout << node->data << " "; /* then recur on left subtree */ printPreorder(node->left); /* now recur on right subtree */ printPreorder(node->right); } /* Driver program to test above functions*/ int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << "\nPreorder traversal of binary tree is \n"; printPreorder(root); cout << "\nInorder traversal of binary tree is \n"; printInorder(root); cout << "\nPostorder traversal of binary tree is \n"; printPostorder(root); return 0; }