Create sample.java

[Prateeshtalasu]

No description provided.

[super30admin]

The student's solution contains two separate backtracking problems: combinationSum and addOperators. Here's the evaluation for each:

1. combinationSum:

   • Correctness: The solution correctly implements the backtracking approach to find all combinations of numbers that sum up to the target. It handles both including and excluding the current candidate.
   • Time Complexity: The time complexity is O(2^N), where N is the number of candidates, due to the recursive branching.
   • Space Complexity: The space complexity is O(target/min(candidates)) due to the recursion stack and the storage of combinations.
   • Code Quality: The code is clean and follows good practices. The helper method is appropriately named, and the logic is clear.
   • Efficiency: The solution is efficient for the problem, but no further optimizations are needed.

2. addOperators:

   • Correctness: The solution correctly generates all possible expressions by inserting '+', '-', or '*' between digits and evaluates them to match the target. It handles leading zeros appropriately.
   • Time Complexity: The time complexity is O(4^N), where N is the length of the string, due to the four choices (no operator, '+', '-', '*') at each step.
   • Space Complexity: The space complexity is O(N) due to the recursion stack and the path string.
   • Code Quality: The code is well-structured and readable. The backtracking logic is clear, and the handling of edge cases (like leading zeros) is correct.
   • Efficiency: The solution is efficient for the problem, but no further optimizations are needed.

General Feedback:

• The student has demonstrated a good understanding of backtracking problems.
• The code is well-organized and follows best practices.
• Both solutions handle edge cases appropriately (e.g., leading zeros in addOperators).
• The variable names are descriptive, and the logic is easy to follow.