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

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;
}

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;
}

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

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

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))); 
}

/* 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

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;
}

#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

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;
}

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.

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

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

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])

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

What will the below code snippet do?

C++

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

#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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