more optimized

[Anshuman7080]

Use of std::vector: The code now uses std::vector for dynamic sizing, which improves memory management and makes it easier to handle resizing.
Sorting Function: The sorting function is encapsulated and utilizes a lambda function to simplify the sorting criteria.
Elimination of Unnecessary Deletions: Instead of deleting elements, the addition logic directly fills the resulting array.
Reduced Code Complexity: Simplified the logic for adding matrices, reducing the number of conditions and loops.
Improved Display Logic: The display logic checks for non-zero values in a more straightforward way.