#1981
Minimize the Difference Between Target and Chosen Elements
MediumArrayDynamic ProgrammingMatrixDynamic ProgrammingSet Operations
Approaches
Brute ForceOptimal
Complexity Comparison
| Brute Force | Optimal Solution★ | |
|---|---|---|
| Time | O(n^m) | O(m * n * k), where k is the maximum number of possible sums. |
| Space | O(1) | O(k), where k is the number of unique sums stored. |
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Intuition
Time O(m * n * k), where k is the maximum number of possible sums.Space O(k), where k is the number of unique sums stored.
The optimal approach uses dynamic programming to efficiently track possible sums as we iterate through the rows. This reduces the number of combinations we need to consider by only keeping sums that are close to the target.
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Algorithm
4 steps- 1Step 1: Initialize a set to store possible sums starting with 0.
- 2Step 2: For each row in the matrix, update the set of possible sums by adding each element of the row to each existing sum in the set.
- 3Step 3: After processing all rows, find the closest sum to the target from the set of possible sums.
- 4Step 4: Calculate the absolute difference between this closest sum and the target.
solution.py9 lines
1def minAbsDifference(mat, target):
2 possible_sums = {0}
3 for row in mat:
4 new_sums = set()
5 for num in row:
6 for s in possible_sums:
7 new_sums.add(s + num)
8 possible_sums = new_sums
9 return min(abs(s - target) for s in possible_sums)ℹ
Complexity note: This complexity is more efficient than brute force because we avoid generating all combinations explicitly and instead build sums iteratively, focusing only on those that are feasible.
- 1Dynamic programming can significantly reduce the number of combinations to consider.
- 2Tracking possible sums allows us to focus on feasible solutions rather than generating all combinations.
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