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$ curl repovive.com/roadmaps/greedy-algorithms/practice-problems/k-negations-implementation

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$ curl repovive.com/roadmaps/greedy-algorithms/practice-problems/k-negations-implementation

Repovive

K Negations - Implementation - Practice Problems | Greedy Algorithms | Repovive

Repovive.

Greedy Algorithms8 sections · 317 units14h total

Open in Course

K Negations - Implementation

The code

Here is the solution:

function largestSumAfterKNegations(A, k)
 sort A ascending
 i := 0
 while k > 0 and i < length and A[i] < 0
 A[i] := -A[i]
 i := i + 1
 k := k - 1
 if k % 2 = 1 then
 minVal := min(A)
 sum := sum(A) - 2 * minVal
 return sum
 return sum(A)

Time: $O(n \log n)$ . Space: $O(1)$ .

Flip all negatives first. If odd flips remain, subtract twice the smallest (one flip changes it from $+x$ to $-x$ , a difference of $2x$ ).