What is LeetCode 494 Target Sum problem?

Array nums, target S: count ways to assign + or - to sum to S. Transforms to subset sum via (sum(nums) + S)/2.

How to solve LeetCode 494 with dynamic programming?

1D DP: dp[i] = ways to make i. Update backward per num. Return dp[(total + S)//2] after checks.

What's the time complexity for Target Sum LeetCode?

O(n * sum(nums)/2), space O(sum/2). Efficient for constraints.

LeetCode 494's Target Sum: The DP Magic That Turns Chaos into Counts

Staring down an array of numbers, target in sight: how many ways to + or - them to hit it? LeetCode 494's answer lies in a slick DP transform that's pure coding poetry.

theAIcatchup Apr 09, 2026 3 min read

Step-by-step visual trace of DP array updating for LeetCode 494 Target Sum

⚡ Key Takeaways

Transform Target Sum to subset sum: P = (total + S)/2 unlocks DP magic. 𝕏
Backward loop in DP prevents reuse — key to correctness. 𝕏
Visual tracers like TraceLit build intuition beyond rote solving. 𝕏

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#Algorithm Interview #Dynamic Programming #LeetCode 494 #Target Sum #algorithm visualization #algorithms #subset-sum

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Originally reported by Dev.to

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