Create Tree_Diagonal_Traversal.cpp

Tree_Diagonal_Traversal/Tree_Diagonal_Traversal.cpp

@@ -0,0 +1,84 @@
+/*
+ * Diagonal Traversal of Binary tree
+ */
+
+#include <iostream>
+#include <vector>
+#include <unordered_map>
+
+using namespace std;
+
+// Data Structure to store a Binary Tree node
+struct Node {
+    int data;
+    Node *left, *right;
+
+    Node(int data) {
+        this->data = data;
+        this->left = this->right = NULL;
+    }
+};
+
+// Recursive function to perform preorder traversal on the tree and
+// Fill the mao with diagonal elements
+void printDiagonal(Node* node, int diagonal, unordered_map<int, vector<int> >& map)
+{
+    // Base case: empty tree
+    if (node == NULL) {
+        return;
+    }
+
+    // insert the current node into the current diagonal
+    map[diagonal].push_back(node->data);
+
+    // recur for the left subtree by increasing diagonal by 1
+    printDiagonal(node->left, diagonal + 1, map);
+
+    // Recur for the right subtree with the same diagonal
+    printDiagonal(node->right, diagonal, map);
+}
+
+
+// Function to print the diagonal elemtns of a given binary tree
+void printDiagonal(Node* root) {
+    // create an empty map to store the diagonal element by every slope
+    unordered_map<int, vector<int> > map;
+
+    // perform preorder traversal on the tree and fill the map
+    printDiagonal(root, 0, map);
+
+    // traverse the map and print diagonal elements
+    for (int i = 0; i < map.size(); i++) {
+        for (int j = 0; j < map[i].size(); j++) {
+            cout << map[i][j] << " ";
+        }
+        cout << endl;
+    }
+    cout << endl;
+}
+int main() {
+/* construct the following tree
+              1
+            /   \
+           /     \
+          2        3
+         /      /   \
+        /      /     \
+       4      5       6
+            /   \
+           /     \
+          7       8
+*/
+    Node* root = new Node(1);
+    root->left = new Node(2);
+    root->right = new Node(3);
+    root->left->left = new Node(4);
+    root->right->left = new Node(5);
+    root->right->right = new Node(6);
+    root->right->right->left = new Node(7);
+    root->right->right->right = new Node(8);
+
+    printDiagonal(root);
+    return 0;
+}
+