feat: add Swap Odd and Even Bits algorithm

[AliAlimohammadi]

Description

Adds the Swap Odd and Even Bits algorithm to the bit manipulation module.

This algorithm swaps the odd and even bits of a 32-bit unsigned integer using bitwise operations.

Implementation Details

• Uses bitwise AND with masks (0xAAAAAAAA for even bits, 0x55555555 for odd bits)
• Shifts even bits right and odd bits left to perform the swap
• Time Complexity: O(1)
• Space Complexity: O(1)

Testing

• Added comprehensive unit tests covering edge cases
• All tests pass with cargo test
• Code formatted with cargo fmt
• No clippy warnings

Checklist

• I have tested the code
• I have run cargo fmt
• I have run cargo clippy
• I have added documentation
• I have added tests

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.62%. Comparing base (6bed9d5) to head (ce070ff).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #964   +/-   ##
=======================================
  Coverage   95.62%   95.62%           
=======================================
  Files         338      339    +1     
  Lines       22052    22078   +26     
=======================================
+ Hits        21088    21113   +25     
- Misses        964      965    +1     

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[AliAlimohammadi]

@siriak, this is ready to be merged.

[Copilot]

Pull request overview

This PR adds a new Swap Odd and Even Bits algorithm to the bit manipulation module. The algorithm swaps bits at even positions (0, 2, 4, 6, etc.) with bits at odd positions (1, 3, 5, 7, etc.) in a 32-bit unsigned integer using bitwise masks and shifts. The implementation achieves O(1) time and space complexity.

Key Changes

• Implements swap_odd_even_bits function using bitwise operations with masks 0xAAAAAAAA and 0x55555555
• Adds comprehensive unit tests covering edge cases including all bits set, alternating patterns, and powers of two
• Includes formatting improvements to DIRECTORY.md for consistency in naming conventions

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/bit_manipulation/swap_odd_even_bits.rs	New algorithm implementation with function documentation and comprehensive unit tests
src/bit_manipulation/mod.rs	Adds module declaration and public export for the new algorithm
DIRECTORY.md	Adds entry for the new algorithm; includes unrelated formatting improvements for consistency (e.g., "N-Queens", "ROT13", "AES")

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[siriak]

Looks good, thanks!