# Python Program to Toggle First and Last Bits of a Number

The task is to toggle the first bit and last bit of a given number in python.

Toggling:

A toggling operation changes the value of a bit from 0 to 1 and from 1 to 0.

Examples:

Example1:

Input:

Given Number =12

Output:

The Number after toggling the first bit and last bit of a given number{ 12 } =  5

Example2:

Input:

Given Number =4

Output:

The Number after toggling the first bit and last bit of a given number{ 4 } =  1

## Program to Toggle First and Last Bits of a Number in Python

Below are the ways to toggle the first bit and last bit of a given number in python:

### Method #1: Using Right Shift (>>)Operator (Static Input)

Approach:

• Give the number as static input and store it in a variable.
• Pass the given number as an argument to the takeLastandFirstsetbits function.
• Create a  function to say takeLastandFirstsetbits which takes the given number as an argument.
• Apply the or(|) operator to the given number and given_numb >> 1(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 2(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 4(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 8(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 16(Right Shift) and store it in the same variable.
• Add 1 to the given number and right shift the result by 1 and store it in another variable.
• Return the above result +1.
• Pass the given number as an argument to the toggleFirstandLastbits function.
• Create a  function to say toggleFirstandLastbits which takes the given number as an argument and returns the number after toggling the first and last bits of a given number.
• Check if the given number is equal to 1 using the if conditional statement.
• If the statement is true, then return 0.
• Return the Xor result of the given number and takeLastandFirstsetbits(gven_numb).
• Print the number after toggling the first bit and last bit of a given number.
• The Exit of the Program.

Below is the implementation:

# Create a  function to say takeLastandFirstsetbits which takes the given number as an
# argument.

def takeLastandFirstsetbits(gven_numb):
# Apply the or(|) operator to the given number and given_numb >> 1(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 1
# Apply the or(|) operator to the given number and given_numb >> 2(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 2
# Apply the or(|) operator to the given number and given_numb >> 4(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 4
# Apply the or(|) operator to the given number and given_numb >> 8(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 8
# Apply the or(|) operator to the given number and given_numb >> 16(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 16
# Add 1 to the given number and right shift the result by 1 and store it in another
# variable.
p = (gven_numb + 1) >> 1
# Return the above result +1.
return (p + 1)

# Create a  function to say toggleFirstandLastbits which takes the given number as an
# argument and returns the number after toggling the first and last bits of a given number.

def toggleFirstandLastbits(gven_numb):
# Check if the given number is equal to 1 using the if conditional statement.
if (gven_numb == 1):
# If the statement is true, then return 0.
return 0
# Return the Xor result of the given number and takeLastandFirstsetbits(gven_numb).
return gven_numb ^ takeLastandFirstsetbits(gven_numb)

# Give the number as static input and store it in a variable.
# Pass the given number as an argument to the takeLastandFirstsetbits function.
# Pass the given number as an argument to the toggleFirstandLastbits function.
gven_numb = 12
# Print the number after toggling the first bit and last bit of a given number.
print("The Number after toggling the first bit and last bit of a given number{", gven_numb, "} = ", toggleFirstandLastbits(
gven_numb))


Output:

The Number after toggling the first bit and last bit of a given number{ 12 } =  5

### Method #2: Using Right Shift (>>)Operator (User Input)

Approach:

• Give the number as user input using the int(input()) function and store it in a variable.
• Pass the given number as an argument to the takeLastandFirstsetbits function.
• Create a  function to say takeLastandFirstsetbits which takes the given number as an argument.
• Apply the or(|) operator to the given number and given_numb >> 1(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 2(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 4(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 8(Right Shift) and store it in the same variable.
• Apply the or(|) operator to the given number and given_numb >> 16(Right Shift) and store it in the same variable.
• Add 1 to the given number and right shift the result by 1 and store it in another variable.
• Return the above result +1.
• Pass the given number as an argument to the toggleFirstandLastbits function.
• Create a  function to say toggleFirstandLastbits which takes the given number as an argument and returns the number after toggling the first and last bits of a given number.
• Check if the given number is equal to 1 using the if conditional statement.
• If the statement is true, then return 0.
• Return the Xor result of the given number and takeLastandFirstsetbits(gven_numb).
• Print the number after toggling the first bit and last bit of a given number.
• The Exit of the Program.

Below is the implementation:

# Create a  function to say takeLastandFirstsetbits which takes the given number as an
# argument.

def takeLastandFirstsetbits(gven_numb):
# Apply the or(|) operator to the given number and given_numb >> 1(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 1
# Apply the or(|) operator to the given number and given_numb >> 2(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 2
# Apply the or(|) operator to the given number and given_numb >> 4(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 4
# Apply the or(|) operator to the given number and given_numb >> 8(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 8
# Apply the or(|) operator to the given number and given_numb >> 16(Right Shift) and
# store it in the same variable.
gven_numb = gven_numb | gven_numb >> 16
# Add 1 to the given number and right shift the result by 1 and store it in another
# variable.
p = (gven_numb + 1) >> 1
# Return the above result +1.
return (p + 1)

# Create a  function to say toggleFirstandLastbits which takes the given number as an
# argument and returns the number after toggling the first and last bits of a given number.

def toggleFirstandLastbits(gven_numb):
# Check if the given number is equal to 1 using the if conditional statement.
if (gven_numb == 1):
# If the statement is true, then return 0.
return 0
# Return the Xor result of the given number and takeLastandFirstsetbits(gven_numb).
return gven_numb ^ takeLastandFirstsetbits(gven_numb)

# Give the number as user input using the int(input()) function and store it in a variable.
gven_numb = int(input("Enter some random number = "))
# Pass the given number as an argument to the takeLastandFirstsetbits function.
# Pass the given number as an argument to the toggleFirstandLastbits function.
# Print the number after toggling the first bit and last bit of a given number.
print("The Number after toggling the first bit and last bit of a given number{", gven_numb, "} = ", toggleFirstandLastbits(
gven_numb))


Output:

Enter some random number = 4
The Number after toggling the first bit and last bit of a given number{ 4 } = 1