added level order traversal using bfs

Author: ayush523

Trees/level-order-traversal_usingBFS.cpp

@@ -0,0 +1,61 @@
+#include <iostream>
+using namespace std;
+
+struct Node
+{
+    int key;
+    Node* left;
+    Node* right;
+
+    Node(int k)
+    {
+        key = k;
+        left = NULL;
+        right = NULL;
+    }
+};
+
+int height(Node *node)
+{
+    if (node == NULL)
+       return -1;
+    int lheight = height(node->left);
+    int rheight = height(node->right);
+    return max(lheight, rheight) + 1;
+}
+
+void print_level(Node *node, int level)
+{
+    if (node == NULL)
+       return;
+    else if (level == 0)
+       cout << node->key << " ";
+    else if (level > 0)
+    {
+        print_level(node->left, level-1);
+        print_level(node->right, level-1);
+    }
+}
+
+void levelorder_traversal(Node *root)
+{
+    
+    for (int level=0; level <= height(root); level++)
+        print_level(root, level);
+}
+
+int main()
+{
+    Node *root=new Node(10);
+	root->left=new Node(20);
+	root->right=new Node(30);
+	root->left->left=new Node(40);
+	root->left->right=new Node(50);
+	root->right->left=new Node(60);
+	root->right->right=new Node(70);
+
+    cout << "Levelorder Traversal using recursion: ";
+    levelorder_traversal(root);
+    cout << endl;
+    return 0;
+}