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$ curl repovive.com/roadmaps/math-fundamentals/combinations/subsets-ii-implementation

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$ curl repovive.com/roadmaps/math-fundamentals/combinations/subsets-ii-implementation

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Subsets II - Implementation - Combinations | Math Fundamentals | Repovive

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Math Fundamentals18 sections · 842 units13h total

Open in Course

Subsets II - Implementation

The pseudocode

Here is the full solution:


function subsetsWithDup(nums)
    sort(nums)
    result := []
    backtrack(nums, 0, [], result)
    return result

function backtrack(nums, start, current, result)
    add copy of current to result
    for i from start to length of nums - 1
        // Skip duplicates
        if i > start and nums[i] = nums[i-1] then
            continue
        add nums[i] to current
        backtrack(nums, i + 1, current, result)
        remove last element from current

Time: $O(n \times 2^n)$ for generating all subsets. Space: $O(n)$ for recursion depth. The sorting takes $O(n \log n)$ but is dominated by subset generation.