check_even_odd.cpp File Reference

Implementation to [Check if a number is Even or Odd using Bitwise Operator] (https://www.log2base2.com/c-examples/bitwise/odd-or-even-program-in-c-using-bitwise-operator.html) More...

#include <cassert>
#include <cstdint>
#include <iostream>
#include <string>

Include dependency graph for check_even_odd.cpp:

Go to the source code of this file.

Namespaces
namespace	bit_manipulation
	for std::string
namespace	even_odd
	Functions for checking if a number is even or odd using bitwise operations.

Functions
bool	bit_manipulation::even_odd::is_even (std::int64_t N)
	Checks if a number is even or odd using bitwise AND.
static void	test ()
	Self-test implementations.
int	main ()
	Main function.

Detailed Description

Implementation to [Check if a number is Even or Odd using Bitwise Operator] (https://www.log2base2.com/c-examples/bitwise/odd-or-even-program-in-c-using-bitwise-operator.html)

Given an integer N, determine whether it is even or odd using bitwise manipulation. The least significant bit (LSB) of a binary number determines its parity:

• If the LSB is 0, the number is even.
• If the LSB is 1, the number is odd.

This can be checked efficiently using the bitwise AND operator (&) with 1.

• If (N & 1) == 0, N is even.
• If (N & 1) == 1, N is odd.

Example: Consider 8-bit binary representations of two numbers: Number: 10 (decimal) -> 00001010 (binary) LSB = 0 -> Even number

Number: 13 (decimal) -> 00001101 (binary) LSB = 1 -> Odd number

In both cases, evaluating (N & 1) isolates the LSB:

• For 10: 00001010 & 00000001 = 0 (Even)
• For 13: 00001101 & 00000001 = 1 (Odd)

Worst Case Time Complexity: O(1) Space Complexity: O(1)

Author

Vedant Mukhedkar

Definition in file check_even_odd.cpp.

Function Documentation

is_even()

bool bit_manipulation::even_odd::is_even

(

std::int64_t

N

)

Checks if a number is even or odd using bitwise AND.

Parameters

N	The number to check.

Returns

"Even" if N is even, "Odd" if N is odd.

Definition at line 55 of file check_even_odd.cpp.

                                   {
            return (N & 1) == 0 ? true : false;
        }

main()

int main

(

void

)

Main function.

Returns

0 on exit

Definition at line 90 of file check_even_odd.cpp.

           {
    test();  // run self-test implementations
    return 0;
}

test()

void test ( )

static

Self-test implementations.

Returns

void

Definition at line 66 of file check_even_odd.cpp.

                   {
    using bit_manipulation::even_odd::is_even;
 
    // Test Even numbers
    assert(is_even(0) == true);
    assert(is_even(2) == true);
    assert(is_even(100) == true);
    assert(is_even(-4) == true);
    assert(is_even(-1000) == true);
 
    // Test Odd numbers
    assert(is_even(1) == false);
    assert(is_even(3) == false);
    assert(is_even(101) == false);
    assert(is_even(-5) == false);
    assert(is_even(-999) == false);
 
    std::cout << "All test cases successfully passed!" << std::endl;
}