Tree Traversal Question issue no #44

DSA/inorder_tree_traversal.cpp

@@ -0,0 +1,58 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+// Definition for a binary tree node.
+struct TreeNode {
+    int val;
+    TreeNode *left;
+    TreeNode *right;
+
+    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+};
+
+// Function to insert a node in a Binary Search Tree (BST)
+TreeNode* insert(TreeNode* root, int val) {
+    if (root == NULL) {
+        return new TreeNode(val);
+    }
+    if (val < root->val) {
+        root->left = insert(root->left, val);
+    } else {
+        root->right = insert(root->right, val);
+    }
+    return root;
+}
+
+// Inorder Traversal of the Binary Tree
+void inorderTraversal(TreeNode* root) {
+    if (root == NULL) {
+        return;
+    }
+    inorderTraversal(root->left);  // Traverse left subtree
+    cout << root->val << " ";      // Visit node
+    inorderTraversal(root->right); // Traverse right subtree
+}
+
+int main() {
+    TreeNode* root = NULL;
+    int n, val;
+    // Taking number of elements as input
+    cout << "Enter the number of nodes: ";
+    cin >> n;
+    // Taking node values as input
+    cout << "Enter the values of the nodes:\n";
+    for (int i = 0; i < n; i++) {
+        cin >> val;
+        root = insert(root, val); // Insert each value in the BST
+    }
+    // Performing inorder traversal
+    cout << "Inorder Traversal: ";
+    inorderTraversal(root);
+    cout << endl;
+    return 0;
+}
+
+// Enter the number of nodes: 5
+// Enter the values of the nodes:
+// 4 2 5 1 3
+// Inorder Traversal: 1 2 3 4 5

DSA/preorder_tree_traversal.cpp

@@ -0,0 +1,58 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+// Definition of a binary tree node
+struct TreeNode {
+    int val;
+    TreeNode* left;
+    TreeNode* right;
+
+    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+};
+
+// Function to perform preorder traversal
+void preorderTraversal(TreeNode* root) {
+    if (root == NULL) return;
+    // Visit the root node
+    cout << root->val << " ";
+    // Traverse the left subtree
+    preorderTraversal(root->left);
+    // Traverse the right subtree
+    preorderTraversal(root->right);
+}
+
+// Function to create a binary tree from user input
+TreeNode* createTree() {
+    int val;
+    cout << "Enter node value (-1 for NULL): ";
+    cin >> val;
+    // Base case for recursion
+    if (val == -1) return NULL;
+    // Create a new node with the given value
+    TreeNode* root = new TreeNode(val);
+    // Recursively create the left and right subtrees
+    cout << "Enter left child of " << val << ": ";
+    root->left = createTree();
+    cout << "Enter right child of " << val << ": ";
+    root->right = createTree();
+    return root;
+}
+
+int main() {
+    // Create the binary tree
+    TreeNode* root = createTree();
+    // Perform preorder traversal
+    cout << "Preorder Traversal: ";
+    preorderTraversal(root);
+    cout << endl;
+    return 0;
+}
+
+// Enter node value (-1 for NULL): 1
+// Enter left child of 1: 2
+// Enter left child of 2: -1
+// Enter right child of 2: -1
+// Enter right child of 1: 3
+// Enter left child of 3: -1
+// Enter right child of 3: -1
+// Preorder Traversal: 1 2 3