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🔥Combination Sum: Backtracking Target ExplorerMedium
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MediumArrays & Hashing•Acceptance: 71.2%

Combination Sum: Backtracking Target Explorer

Targeted in FAANG & Tech OA:AmazonGoogleMicrosoft
Real-World Engineering Context
Used in ATM currency cash disbursement algorithms, shopping cart promotional coupon optimizers, and cloud server resource bin-packing.
Given an array of distinct integers `candidates` and a target integer `target`, return a list of all unique combinations of `candidates` where the chosen numbers sum to `target`. You may return the combinations in any order. The same number may be chosen from `candidates` an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.

Sample Test Cases

Input: [[2,3,6,7],7]
Expected: [[2,2,3],[7]]
Input: [[2,3,5],8]
Expected: [[2,2,2,2],[2,3,3],[3,5]]
Input: [[2],1]
Expected: []

Constraints

  • 1 <= candidates.length <= 30
  • 2 <= candidates[i] <= 40
  • All elements of candidates are distinct.
  • 1 <= target <= 40
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