# Binary Tree

 Question 1
Consider a complete binary tree with 7 nodes. Let A denote the set of first 3 elements obtained by performing Breadth-First Search (BFS) starting from the root. Let B denote the set of first 3 elements obtained by performing Depth-First Search (DFS) starting from the root.

The value of |A-B| is _____________
 A 3 B 4 C 1 D 2
GATE CSE 2021 SET-2   Data Structure
Question 1 Explanation:
 Question 2
The post-order traversal of binary tree is ACEDBHIGF. The pre-order traversal is
 A A B C D E F G H I B F B A D C E G I H C F A B C D E G H I D A B D C E F G I H
ISRO CSE 2020   Data Structure
Question 2 Explanation:
 Question 3
Let T be a full binary tree with 8 leaves. (A full binary tree has every level full.) Suppose two leaves a and b of T are chosen uniformly and independently at random. The expected value of the distance between a and b in T (i.e., the number of edges in the unique path between a and b) is (rounded off to 2 decimal places) ___________ .
 A 2.5 B 4.25 C 6.5 D 3.75
GATE CSE 2019   Data Structure
Question 3 Explanation:
 Question 4 Which traversals of Tree-1 and Tree-2, respectively, will produce the same sequence?
 A Preorder, postorder B Postorder, inorder C Postorder, preorder D None of these
ISRO CSE 2018   Data Structure
Question 4 Explanation:
 Question 5
The postorder traversal of a binary tree is 8,9,6,7,4,5,2,3,1. The inorder traversal of the same tree is 8,6,9,4,7,2,5,1,3. The height of a tree is the length of the longest path from the root to any leaf. The height of the binary tree above is ______.
 A 4 B 5 C 3 D 6
GATE CSE 2018   Data Structure
Question 5 Explanation:
 Question 6 If the post order traversal gives ab -cd * + then the label of the nodes 1,2,3.. will be
 A + , -, *, a,b,c,d B a, -,b,+,c,*,d C a,b,c,d,-,*,+ D -,a,b,+,*,c,d
ISRO CSE 2017   Data Structure
Question 6 Explanation:
 Question 7
A complete binary tree with n non-leaf nodes contains
 A $\log_{2}n$ nodes B n+1 nodes C 2n nodes D 2n+1 nodes
ISRO CSE 2016   Data Structure
Question 7 Explanation:
 Question 8
Consider the following New-order strategy for traversing a binary tree:
Visit the root;
Visit the right sub tree using New-order;
Visit the left sub tree using New-order;
The New-order traversal of the expression tree corresponding to the reverse polish expression
3 4 * 5 - 2 ^ 6 7 * 1 + - is given by:
 A + -167*2^5-34* B - +1*67^2-5*34 C - +1*76^2-5*43 D 1 76*+2543*-^-
GATE CSE 2016 SET-2   Data Structure
Question 8 Explanation:
 Question 9
Consider a binary tree T that has 200 leaf nodes. Then, the number of nodes in T that have exactly two children are ________.
 A 99 B 100 C 199 D 149
GATE CSE 2015 SET-3   Data Structure
Question 9 Explanation:
 Question 10
A binary tree T has 20 leaves. The number of nodes in T having two children is _______.
 A 20 B 19 C 39 D 9
GATE CSE 2015 SET-2   Data Structure
Question 10 Explanation:
There are 10 questions to complete.

### 5 thoughts on “Binary Tree”

1. In Question no 8.
Sir please correct option no C)
to
-+1*76^2-5*43

• Thank You Abhishek Chavle,

2. Question no 47
Options A , C , D are correct

• 3. 