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* Create check_even_odd.cpp Implementation to Check if a number is Even or Odd using Bitwise Operator * Update check_even_odd.cpp * Create factorial_top_down_dp.cpp * Delete dynamic_programming/factorial_top_down_dp.cpp Deleted the one file as there was 2 files in the commit * Create factorial_top_down_dp.cpp * Delete dynamic_programming/factorial_top_down_dp.cpp * Update bit_manipulation/check_even_odd.cpp Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com> * Update bit_manipulation/check_even_odd.cpp Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com> * Update bit_manipulation/check_even_odd.cpp Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com> * Update bit_manipulation/check_even_odd.cpp Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com> * Update check_even_odd.cpp modified * Update check_even_odd.cpp reverted to boolean to check if number is even or not --------- Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com>
94 lines
2.5 KiB
C++
94 lines
2.5 KiB
C++
/**
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* @file
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* @brief Implementation to [Check if a number is Even or Odd using Bitwise Operator]
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* (https://www.log2base2.com/c-examples/bitwise/odd-or-even-program-in-c-using-bitwise-operator.html)
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*
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* @details
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* Given an integer N, determine whether it is even or odd using bitwise manipulation.
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* The least significant bit (LSB) of a binary number determines its parity:
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* - If the LSB is 0, the number is even.
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* - If the LSB is 1, the number is odd.
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*
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* This can be checked efficiently using the bitwise AND operator (&) with 1.
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* - If (N & 1) == 0, N is even.
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* - If (N & 1) == 1, N is odd.
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*
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* Example:
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* Consider 8-bit binary representations of two numbers:
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* Number: 10 (decimal) -> 00001010 (binary)
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* LSB = 0 -> Even number
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*
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* Number: 13 (decimal) -> 00001101 (binary)
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* LSB = 1 -> Odd number
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*
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* In both cases, evaluating (N & 1) isolates the LSB:
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* - For 10: 00001010 & 00000001 = 0 (Even)
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* - For 13: 00001101 & 00000001 = 1 (Odd)
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*
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* Worst Case Time Complexity: O(1)
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* Space Complexity: O(1)
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*
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* @author [Vedant Mukhedkar](https://github.com/git5v)
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*/
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#include <cassert> /// for assert
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#include <cstdint> /// for uint32_t
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#include <iostream> /// for IO operations
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#include <string> /// for std::string
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/**
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* @namespace bit_manipulation
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* @brief Bit manipulation algorithms
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*/
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namespace bit_manipulation {
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/**
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* @namespace even_odd
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* @brief Functions for checking if a number is even or odd using bitwise operations
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*/
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namespace even_odd {
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/**
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* @brief Checks if a number is even or odd using bitwise AND.
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* @param N The number to check.
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* @returns "Even" if N is even, "Odd" if N is odd.
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*/
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bool is_even(std::int64_t N) {
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return (N & 1) == 0 ? true : false;
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}
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} // namespace even_odd
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} // namespace bit_manipulation
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/**
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* @brief Self-test implementations
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* @returns void
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*/
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static void test() {
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using bit_manipulation::even_odd::is_even;
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// Test Even numbers
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assert(is_even(0) == true);
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assert(is_even(2) == true);
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assert(is_even(100) == true);
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assert(is_even(-4) == true);
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assert(is_even(-1000) == true);
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// Test Odd numbers
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assert(is_even(1) == false);
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assert(is_even(3) == false);
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assert(is_even(101) == false);
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assert(is_even(-5) == false);
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assert(is_even(-999) == false);
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std::cout << "All test cases successfully passed!" << std::endl;
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}
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/**
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* @brief Main function
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* @returns 0 on exit
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*/
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int main() {
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test(); // run self-test implementations
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return 0;
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}
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