Add implementation for leetcode problems 198, 322

[rishigoswamy]

No description provided.

[super30admin]

Strengths:

• The student has implemented the standard bottom-up dynamic programming solution correctly.
• The time and space complexity are optimal.
• The code is concise and easy to understand.

Areas for improvement:

• The parameter name amounts should be changed to amount to match the problem statement and avoid confusion.
• The documentation at the top of the file is incorrect: it describes the House Robber problem. This should be fixed to describe the Coin Change problem.
• Adding inline comments to explain the dp array initialization and the inner loop would make the code more readable.
• The return statement can be written as return dp[amounts] if dp[amounts] != amounts+1 else -1 instead of dp[-1] for clarity. Using dp[-1] is correct because it is the last element, but explicitly using dp[amounts] is more straightforward.