Computer Science Engineering (CSE) Exam  >  Computer Science Engineering (CSE) Questions  >  Let LASTPOST, LASTIN and LASTPRE denote the l... Start Learning for Free
Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?
  • a)
    LASTIN = LASTPOST
  • b)
    LASTIN = LASTPRE
  • c)
    LASTPRE = LASTPOST
  • d)
    None of the above
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a p...
Explanation:

In a complete binary tree, the number of nodes is always a power of 2. Let us consider a complete binary tree with 7 nodes numbered from 1 to 7 in level order traversal. The tree looks like:

```
1
/ \
2 3
/ \ / \
4 5 6 7
```

Let us now traverse the tree in inorder, preorder and postorder and observe the values of LASTIN, LASTPRE and LASTPOST.

Inorder traversal: 4 2 5 1 6 3 7
- LASTIN = 7 (last node visited in inorder traversal)
Preorder traversal: 1 2 4 5 3 6 7
- LASTPRE = 7 (last node visited in preorder traversal)
Postorder traversal: 4 5 2 6 7 3 1
- LASTPOST = 7 (last node visited in postorder traversal)

From the above example, we can see that none of the options (a), (b) or (c) are always true.

Conclusion:

Therefore, the correct answer is option (d) None of the above.
Free Test
Community Answer
Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a p...
The correct option is D LASTIN = LASTPRE
Because of complete binary tree option (D) is always correct
Explore Courses for Computer Science Engineering (CSE) exam

Top Courses for Computer Science Engineering (CSE)

Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer?
Question Description
Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer?.
Solutions for Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Computer Science Engineering (CSE). Download more important topics, notes, lectures and mock test series for Computer Science Engineering (CSE) Exam by signing up for free.
Here you can find the meaning of Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Let LASTPOST, LASTIN and LASTPRE denote the last vertex visited in a postorder, inorder and preorder traversal, respectively, of a complete binary tree. Which of the following is always true?a)LASTIN = LASTPOSTb)LASTIN = LASTPREc)LASTPRE = LASTPOSTd)None of the aboveCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Computer Science Engineering (CSE) tests.
Explore Courses for Computer Science Engineering (CSE) exam

Top Courses for Computer Science Engineering (CSE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev