BackTracking-1

[Mounika8300]

No description provided.

[super30admin]

1. Correctness:

   • CombinationSum.java: The solution correctly implements backtracking to find all combinations of candidates that sum up to the target. It handles the base cases and recursive logic appropriately.
   • ExpressionAdd.java: The solution correctly uses DFS with backtracking to explore all possible operator insertions. It handles leading zeros and multiplication precedence correctly.

2. Time Complexity:

   • CombinationSum.java: The student correctly identifies the time complexity as O(2^n), which is accurate for this backtracking approach.
   • ExpressionAdd.java: The student claims O(n) time complexity, which is incorrect. The actual time complexity is O(4^n) due to the branching factor of 4 (+, -, *, no operator) at each step.

3. Space Complexity:

   • CombinationSum.java: The student correctly identifies the space complexity as O(n), which accounts for the recursion stack.
   • ExpressionAdd.java: The student claims O(n) space complexity, which is incorrect. The actual space complexity is O(n) due to the recursion stack, but the explanation should clarify this.

4. Code Quality:

   • CombinationSum.java: The code is well-structured and readable. The use of this.result is unnecessary since the variable is already in scope.
   • ExpressionAdd.java: The code is generally clean and readable. The use of System.out.println(currentStr) is unnecessary and should be removed for production code.

5. Efficiency:

   • CombinationSum.java: The solution is efficient for the problem. No major optimizations are needed.
   • ExpressionAdd.java: The solution is efficient but could benefit from a comment explaining the handling of multiplication precedence (lastOperand).