What is the output of the following code snippet? C++ #include <iostream> using namespace std; void fun(int& num, int k) { num &= (~(1 << k)); } int main() { int num = 7; int k = 1; fun(num, k); cout << num << endl; return 0; } C #include <stdio.h> void fun(int* num, int k) { *num &= (~(1 << k)); } int main() { int num = 7; int k = 1; fun(&num, k); printf("%d ", num); return 0; } Java public class Main { public static void fun(int[] num, int k) { num[0] &= (~(1 << k)); } public static void main(String[] args) { int[] num = {7}; int k = 1; fun(num, k); System.out.println(num[0]); } } Python def fun(num, k): num[0] &= ~(1 << k) num = [7] k = 1 fun(num, k) print(num[0]) JavaScript function fun(num, k) { num[0] &= ~(1 << k); } let num = [7]; let k = 1; fun(num, k); console.log(num[0]);

It will unset the kth bit of num

It will unset the all bits of num

It will clear all the bits of bits

What will the below code snippet do? C++ #include <iostream> using namespace std; int main() { int num = 5; cout << (~num + 1) << endl; return 0; } C #include <stdio.h> int main() { int num = 5; printf("%d ", (~num + 1)); return 0; } Java public class Main { public static void main(String[] args) { int num = 5; System.out.println(~num + 1); } } Python num = 5 print(~num + 1) JavaScript let num = 5; console.log(~num + 1);

It will print 2's complement of a number.

It will print 1.s complement of a number.

Quiz about Top MCQs on Bitwise Algorithms and Bit Manipulations with Answers

Question 1

What is the return value of following function for arr[] = {9, 12, 2, 11, 2, 2, 10, 9, 12, 10, 9, 11, 2} and n is size of this array.

C++

int fun(int arr[], int n) { int x = arr[0]; for (int i = 1; i < n; i++) x = x ^ arr[i]; return x; }

C

int fun(int arr[], int n) { int x = arr[0]; for (int i = 1; i < n; i++) x = x ^ arr[i]; return x; }

Java

public int fun(int[] arr) {     int x = arr[0];     for (int i = 1; i < arr.length; i++)         x = x ^ arr[i];     return x; }

Python

def fun(arr): x = arr[0] for i in range(1, len(arr)): x ^= arr[i] return x

JavaScript

function fun(arr) { let x = arr[0]; for (let i = 1; i < arr.length; i++) x ^= arr[i]; return x; }

0
9
12
2

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Question 2

What does the following C expression do? x = (x<<1) + x + (x>>1);

Multiplies an integer with 7
Multiplies an integer with 3.5
Multiplies an integer with 3
Multiplies an integer with 8

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Question 3

What does the following expression do?

 x = x & (x-1)

Sets all bits as 1
Makes x equals to 0
Turns of the rightmost set bit
Turns of the leftmost set bit

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Question 4

Consider the following code snippet for checking whether a number is power of 2 or not.

C++

/* Incorrect function to check if x is power of 2*/ bool isPowerOfTwo (unsigned int x) { return (!(x&(x-1))); }

C

/* Incorrect function to check if x is power of 2*/ bool isPowerOfTwo (unsigned int x) { return (!(x&(x-1))); }

Java

// Incorrect function to check if x is power of 2 public static boolean isPowerOfTwo(unsigned int x) {   return (x & (x - 1)) == 0; }

Python

# Incorrect function to check if x is power of 2 def is_power_of_two(x): return (x & (x - 1)) == 0

JavaScript

// Incorrect function to check if x is power of 2 function isPowerOfTwo(x) { return (x & (x - 1)) === 0; }

What is wrong with above function?

It does reverse of what is required
It works perfectly fine for all values of x.
It does not work for x = 0
It does not work for x = 1

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Question 5

What is the output of the following code snippet?

C++

#include <iostream> using namespace std;  void fun(int& num, int k) { num &= (~(1 << k)); } int main() {     int num = 7;     int k = 1;     fun(num, k);     cout << num << endl;     return 0; }

C

#include <stdio.h>  void fun(int* num, int k) { *num &= (~(1 << k)); } int main() {     int num = 7;     int k = 1;     fun(&num, k);     printf("%d\n", num);     return 0; }

Java

public class Main {     public static void fun(int[] num, int k) { num[0] &= (~(1 << k)); }     public static void main(String[] args) {         int[] num = {7};         int k = 1;         fun(num, k);         System.out.println(num[0]);     } }

Python

def fun(num, k): num[0] &= ~(1 << k) num = [7] k = 1 fun(num, k) print(num[0])

JavaScript

function fun(num, k) { num[0] &= ~(1 << k); } let num = [7]; let k = 1; fun(num, k); console.log(num[0]);

It will unset the all bits of num
It will clear all the bits of bits
It will unset the kth bit of num
None

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Question 6

what will do the following code in bit manipulation?

C++

int function(int n) {     if (n % 4 == 0)         return n;     if (n % 4 == 1)         return 1;     if (n % 4 == 2)         return n + 1;     else         return 0; }

C

int function(int n) {     if (n % 4 == 0)         return n;     if (n % 4 == 1)         return 1;     if (n % 4 == 2)         return n + 1;     else         return 0; }

Java

public int function(int n) {     if (n % 4 == 0)         return n;     if (n % 4 == 1)         return 1;     if (n % 4 == 2)         return n + 1;     else         return 0; }

Python

def function(n):     if n % 4 == 0:         return n     if n % 4 == 1:         return 1     if n % 4 == 2:         return n + 1     else:         return 0

JavaScript

function function(n) {     if (n % 4 === 0)         return n;     if (n % 4 === 1)         return 1;     if (n % 4 === 2)         return n + 1;     else         return 0; }

It will return the last set bit in a number.
It will return the first set bit in a number.
It will xor of two numbers.
It will give the xor of numbers from 1 to N.

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Question 7

Right shift(>>) and Left shift(<<) are equivalent to _____ by 2.

Multiply and divide
Divide and multiply
Addition and subtraction
Subtraction and addition

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Question 8

You are given a list of 5 integers and these integers are in the range from 1 to 6. There are no duplicates in list. One of the integers is missing in the list. Which of the following expression would give the missing number. ^ is bitwise XOR operator. ~ is bitwise NOT operator. Let elements of list can be accessed as list[0], list[1], list[2], list[3], list[4]

list[0] ^ list[1] ^ list[2] ^ list[3] ^ list[4]
|list[0] ^ list[1] ^ list[2] ^ list[3] ^ list[4] ^ 1 ^ 2 ^ 3 ^ 4 ^ 5 ^ 6
list[0] ^ list[1] ^ list[2] ^ list[3] ^ list[4] ^ 1 ^ 2 ^ 3 ^ 4 ^ 5
~(list[0] ^ list[1] ^ list[2] ^ list[3] ^ list[4])

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Question 9

If we want to invert all the bits of a number, then which bitwise operator should be used?

~
&
^
|

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Question 10

What will the below code snippet do?

C++

#include <iostream> using namespace std; int main() { int num = 5; cout << (~num + 1) << endl; return 0; }

C

#include <stdio.h> int main() { int num = 5; printf("%d\n", (~num + 1)); return 0; }

Java

public class Main {     public static void main(String[] args) {         int num = 5;         System.out.println(~num + 1);     } }

Python

num = 5 print(~num + 1)

JavaScript

let num = 5; console.log(~num + 1);

It will print 2's complement of a number.
It will print 101.
It will print 1.s complement of a number.
None

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