Consider the following nested representation of binary trees: (X Y Z) indicates Y and Z are the left and right sub stress, respectively, of node X. Note that Y and Z may be NULL, or further nested. Which of the following represents a valid binary tree?

**(A)** (1 2 (4 5 6 7))

**(B)** (1 (2 3 4) 5 6) 7)

**(C)** (1 (2 3 4)(5 6 7))

**(D)** (1 (2 3 NULL) (4 5))

**Answer:** **(C)** **Explanation:** C is fine.

(1 (2 3 4)(5 6 7)) represents following binary tree 1 / \ 2 5 / \ / \ 3 4 6 7

A) (1 2 (4 5 6 7)) is not fine as there are 4 elements in one bracket.

B) (1 (2 3 4) 5 6) 7) is not fine as there are 2 opening brackets and 3 closing.

D) (1 (2 3 NULL) (4 5)) is not fine one bracket has only two entries (4 5)

## Recommended Posts:

- Introduction to Data Structures | 10 most commonly used Data Structures
- Data Structures | Binary Trees | Question 1
- Data Structures | Binary Trees | Question 15
- Data Structures | Binary Trees | Question 3
- Data Structures | Binary Trees | Question 15
- Data Structures | Binary Trees | Question 6
- Data Structures | Binary Search Trees | Question 1
- Data Structures | Binary Search Trees | Question 2
- Data Structures | Balanced Binary Search Trees | Question 2
- Data Structures | Binary Search Trees | Question 3
- Data Structures | Binary Search Trees | Question 4
- Data Structures | Binary Search Trees | Question 5
- Data Structures | Balanced Binary Search Trees | Question 2
- Data Structures | Binary Trees | Question 8
- Data Structures | Binary Trees | Question 9
- Data Structures | Binary Trees | Question 10
- Data Structures | Binary Trees | Question 11
- Data Structures | Binary Search Trees | Question 6
- Data Structures | Binary Trees | Question 12
- Data Structures | Binary Trees | Question 13