Update DIRECTORY.md to Reflect Current R Repository Structures algori…

[Siddhram]

This PR updates DIRECTORY.md to accurately reflect the current state of the R repository. All categories and files have been enumerated to ensure that there are no placeholders, missing entries, or extra items. The update improves maintainability and clarity for contributors navigating the repository.

Key Changes

• Dynamic Programming: Verified that only the following scripts are present in the workspace:
  • 1_knapsack_problem.r (nested), 0/1_knapsack_problem.r, coin_change.r, longest_common_subsequence.r, longest_increasing_subsequence.r, matrix_chain_multiplication.r, minimum_path_sum.r, subset_sum.r.
• Graph Algorithms: Added Bridge Detector and Floyd Warshall.
• Mathematics: Added Catalan Numbers, Modular Exponentiation, Newton Raphson Method, and other key algorithms.
• Quantitative Finance: Updated with Black Scholes, Risk Metrics, and Time Series Analyzer.
• Regression Algorithms: Includes Anova Oneway.
• Search Algorithms: Includes Ternary Search.
• Sorting & String Manipulation: Sections refreshed and completed.
• Important Note: Newly discussed DP scripts (unique_paths.r, profitable_schemes.r, burst_balloons.r, maximal_square.r, decode_ways.r, house_robber.r, wiggle_subsequence.r) are not present in this workspace and therefore not included.

Next Steps (Optional)

• Add the new DP algorithms to dynamic_programming/ and refresh DIRECTORY.md again.
• If these scripts exist in another branch or folder, they can be indexed from there.

Impact

This update ensures the repository documentation accurately reflects the current file structure, making it easier for contributors to navigate and maintain consistency across modules.