Bitwise operators are a powerful set of tools used to manipulate the bits within a data type. For many developers, the concept of bitwise operators can be intimidating. However, with a little practice, you can learn to use them effectively and efficiently. The purpose of this blog post is to provide an overview of some of the important bitwise operators in C and to explore some of the most common interview questions related to bitwise operators. We’ll start by taking a closer look at what bitwise operators are and why they are important, and then we’ll move on to the interview questions. After reading this blog post, you should have a better understanding of the basics of bitwise operators and the most common interview questions about them.
Bitwise operator | C Technical Interview Questions | Mr. Ramana
Q) Compute the sign of an integer?
The MSB bit of a number defines their sign. Negative numbers result if the MSB bit is set.
Q) Detect if two integers have opposite signs?
If the MSB (bit) of the two integers differs, then they have different signs. We can examine the integers’ sign using the EX-OR operator.
We are aware that EX-OR yields a low output for a given input and a high yield for a different input.
E.g.
| BIT1 | BIT2 | BIT1 ^ BIT2 |
| 1 | 1 | 0 |
| 0 | 0 | 0 |
| 1 | 0 | 1 |
| 0 | 1 | 1 |
Let the given integers are “a” and “b”. If the MSB of “a” and “b” is different, the EX-OR of “a” and “b” will be 1. In other words, if “a” and “b” have the opposite signs, then the EX-OR of “a” and “b” will be negative.
Bit manipulation is the act of algorithmically manipulating bits or other pieces of data shorter than a word. Computer programming tasks that require bit manipulation include low-level device control, error detection and correction algorithms, data compression, encryption algorithms, and optimization. For most other tasks, modern programming languages allow the programmer to work directly with abstractions instead of bits that represent those abstractions. Source code that does bit manipulation makes use of the bitwise operations: AND, OR, XOR, NOT, and bit shifts.
Because bit manipulations are processed in parallel, there are times when they can eliminate or drastically reduce the need to loop over a data structure and increase speed by a factor of many. However, the code can become more challenging to write and maintain.
We will go over a few of these intriguing bit manipulation hacks and interview questions in this post:
Q) Write a program to check an integer is a power of 2?
I’m writing a quick algorithm to verify the power of two here. If a number has a power of 2, 1 will be the flag.
Note: Because I’m assuming that a bit in a register starts at position 0, the second position actually corresponds to the third set of bits.
| D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
FAQ
What is Bitwise operator in C with example?
Examples of Bitwise Operators Types: Bitwise AND operator (P & Q) = 12 (0000 1100) Binary Ones complement operator (P) = (60) Bitwise XOR operator (P | Q) = 61 in 1100 0011, which equals 0011 1101>>Shift operator (Right)P >> 2 = 15 in 1100 0011, which equals 0000 1111.
Are bitwise operators important for interview?
Is Bit Manipulation Important during Interviews? Yes. The interviewer may not directly inquire about bit manipulation but may pose problems such as “bitmask dp,” “number of subsets,” etc.
How many bitwise operators are in C?
What is bitwise operator used for?
Encryption, compression, graphics, communications over ports or sockets, embedded systems programming, and finite state machines are a few examples of applications for bitwise operations. A bitwise operator operates on a number’s binary representation rather than its value.
