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How to calculate the square of a number using bitwise operators in Python

How to calculate the square of a number using bitwise operators in Python.

Here's a step-by-step tutorial on how to calculate the square of a number using bitwise operators in Python:

Step 1: Understand Bitwise Operators​

Bitwise operators are used to manipulate individual bits of a number. The commonly used bitwise operators in Python are:

  • AND (&): Sets each bit to 1 if both bits are 1.
  • OR (|): Sets each bit to 1 if one of the bits is 1.
  • XOR (^): Sets each bit to 1 if only one of the bits is 1.
  • NOT (~): Inverts all the bits.
  • Left Shift (<<): Shifts the bits to the left, discards the leftmost bits, and fills the rightmost bits with 0.
  • Right Shift (>>): Shifts the bits to the right, discards the rightmost bits, and fills the leftmost bits with the sign bit (0 for positive numbers, 1 for negative numbers).

Step 2: Understand the Squaring Operation​

To calculate the square of a number using bitwise operators, we can use the property that the square of a number is equal to the number multiplied by itself. For example, the square of 5 is 5 * 5 = 25.

Step 3: Implement the Square Calculation​

We can implement the square calculation using bitwise operators in the following steps:

  1. Take the input number and store it in a variable, let's call it num.
  2. Create a variable result and initialize it with 0. This variable will store the square of num.
  3. Initialize a loop that will iterate over the bits of num. We will use the bitwise right shift operator (>>) to shift the bits to the right one by one.
  4. Inside the loop, check if the least significant bit (LSB) of num is 1. We can do this by performing a bitwise AND operation (&) with 1. If the result is 1, it means the LSB is 1, and we add the current value of num to result.
  5. Perform a bitwise left shift operation (<<) on num to move to the next bit.
  6. Repeat steps 4-5 until all the bits of num have been processed.
  7. Return the value of result as the square of the input number.

Step 4: Implement the Solution in Python​

Now, let's implement the above steps in Python:

def calculate_square(num):
    result = 0
    while num:
        if num & 1:
            result += num
        num = num << 1
    return result

Step 5: Test the Solution​

To test the solution, you can call the calculate_square function with different input values. For example:

print(calculate_square(5))  # Output: 25
print(calculate_square(8))  # Output: 64
print(calculate_square(0))  # Output: 0

These examples will print the square of the given numbers using the bitwise calculation.

That's it! You now know how to calculate the square of a number using bitwise operators in Python.