15 Lecture - Level-order Traversal of a Binary Tree

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15 Lecture

CS301

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Level-order Traversal of a Binary Tree

Level-order traversal is a technique used to traverse a binary tree in which nodes are visited level by level, from top to bottom and from left to right. In this traversal method, all nodes at each level are visited before moving on to the next


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  1. What is level-order traversal of a binary tree? A. Visiting the root node first B. Visiting the nodes level by level C. Visiting the left child first D. Visiting the right child first Answer: B

  2. Which data structure can be used to implement level-order traversal? A. Stack B. Queue C. Linked list D. Binary search tree Answer: B

  3. What is the time complexity of level-order traversal? A. O(log n) B. O(n) C. O(n^2) D. O(2^n) Answer: B

  4. In which order are the nodes visited in level-order traversal? A. Left to right, bottom to top B. Right to left, top to bottom C. Left to right, top to bottom D. Right to left, bottom to top Answer: C

  5. Which traversal technique can be used to print the nodes of a binary tree in level-order? A. In-order traversal B. Post-order traversal C. Pre-order traversal D. Level-order traversal Answer: D

  6. What is the space complexity of level-order traversal? A. O(1) B. O(n) C. O(n^2) D. O(2^n) Answer: B

  7. Level-order traversal can be used to solve which type of problem? A. Finding the maximum depth of a binary tree B. Finding the minimum depth of a binary tree C. Finding the sum of all nodes in a binary tree D. Finding the lowest common ancestor of two nodes in a binary tree Answer: A

  8. Which of the following is an advantage of level-order traversal? A. It is faster than other traversal techniques B. It uses less memory than other traversal techniques C. It can be used to find the shortest path between two nodes D. It can be used to sort the nodes in a binary tree Answer: C

  9. What is the main disadvantage of level-order traversal? A. It is difficult to implement B. It requires more memory than other traversal techniques C. It is slower than other traversal techniques D. It does not work for binary trees with an odd number of nodes Answer: B

  10. What is the first node visited in level-order traversal? A. The root node B. The left child of the root node C. The right child of the root node D. It depends on the binary tree Answer: A



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Midterm & Finalterm Prepration
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  1. What is level-order traversal of a binary tree? Answer: Level-order traversal is a technique used to traverse a binary tree in which nodes are visited level by level, from top to bottom and from left to right.

  2. How can level-order traversal be implemented? Answer: Level-order traversal can be implemented using a queue data structure.

  3. What is the time complexity of level-order traversal? Answer: The time complexity of level-order traversal is O(n), where n is the number of nodes in the binary tree.

  4. What is the space complexity of level-order traversal? Answer: The space complexity of level-order traversal is O(n), where n is the number of nodes in the binary tree.

  5. Can level-order traversal be used to find the minimum depth of a binary tree? Answer: Yes, level-order traversal can be used to find the minimum depth of a binary tree.

  6. Can level-order traversal be used to find the maximum depth of a binary tree? Answer: Yes, level-order traversal can be used to find the maximum depth of a binary tree.

  7. Can level-order traversal be used to sort the nodes in a binary tree? Answer: No, level-order traversal cannot be used to sort the nodes in a binary tree.

  8. Can level-order traversal be used to find the lowest common ancestor of two nodes in a binary tree? Answer: Yes, level-order traversal can be used to find the lowest common ancestor of two nodes in a binary tree.

  9. What is the advantage of level-order traversal? Answer: The advantage of level-order traversal is that it can be used to find the shortest path between two nodes.

  10. What is the disadvantage of level-order traversal? Answer: The disadvantage of level-order traversal is that it requires more memory than other traversal techniques.

Level-order traversal is a technique used to visit all the nodes of a binary tree in a level-by-level manner. This traversal technique is also known as breadth-first search (BFS), as it traverses the tree breadth-wise, i.e., it explores all the nodes at the current level before moving on to the next level. The level-order traversal of a binary tree starts from the root node, and then it visits all the nodes at the next level, followed by the nodes at the next level, and so on. This traversal technique can be implemented using a queue data structure. To perform the level-order traversal of a binary tree, we first enqueue the root node into the queue. Then we dequeue the first node from the queue, visit it, and then enqueue its left and right child nodes (if they exist) into the queue. We repeat this process until the queue becomes empty. The time complexity of level-order traversal is O(n), where n is the number of nodes in the binary tree. This is because we visit each node exactly once. The space complexity of level-order traversal is also O(n), as we need to store all the nodes in the queue. Level-order traversal can be used to find the minimum and maximum depth of a binary tree. It can also be used to find the lowest common ancestor of two nodes in a binary tree. One of the major advantages of level-order traversal is that it can be used to find the shortest path between two nodes. However, the disadvantage of level-order traversal is that it requires more memory than other traversal techniques. This is because we need to store all the nodes in the queue. Additionally, if the binary tree is highly unbalanced, then the level-order traversal may not be the best option, as it may require visiting many unnecessary nodes.

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