Q28.Marks: +2.0UGC NET Paper 2: Computer Sc 23rd August 2024 Shift 1
Arrange the following steps in the correct order to solve the Knapsack problem using Dynamic Programming.
(A) Define the base case when the capacity is zero (0) or no items are left to consider
(B) Compute the maximum value that can be obtained using items up to the i-th item and a knapsack capacity of 0
(C) Identify subproblems and their dependencies based on items weights and values
(D) Initialize a table to store results of subproblems
(E) Iterate through each item and each possible Capacity to fill the table
Choose the correct answer from the options given below:
1.(C), (D), (A), (E), (B)
2.(D), (C), (A), (E), (B)
3.(A), (C), (D), (E), (B) ✓ Correct
4.(D), (A), (C), (E), (B)
Solution
The correct answer is 3)(A), (C), (D), (E), (B).
Key Points
Define the base case when the capacity is zero (0) or no items are left to consider: This step ensures that we have a stopping condition for our recursive algorithm. If the knapsack's capacity is zero or there are no items left to consider, the maximum value is zero.
Identify subproblems and their dependencies based on items weights and values: This involves breaking down the main problem into smaller subproblems that can be solved independently. The dependencies will be based on the weights and values of the items.
Initialize a table to store results of subproblems: A table (usually a 2D array) is initialized to store the results of these subproblems. This helps in avoiding the recomputation of the same subproblems and thus improves efficiency.
Iterate through each item and each possible Capacity to fill the table: This step involves populating the table based on the subproblems identified. For each item and each possible capacity, we decide whether to include the item in the knapsack or not.
Compute the maximum value that can be obtained using items up to the i-th item and a knapsack capacity of 0: Finally, compute the maximum value from the filled table. This gives the solution to the original problem.
Thus the correct answer is (A), (C), (D), (E), (B).
Additional Information
The Knapsack problem is a classic example of a combinatorial optimization problem, and dynamic programming provides an efficient way to solve it.
Understanding the structure of the problem and the dependencies between subproblems is crucial for correctly implementing the dynamic programming solution.
The complexity of the dynamic programming approach is generally O(nW), where n is the number of items and W is the capacity of the knapsack. This is much more efficient than the exponential time complexity of the naive recursive solution.