Prefix Sum example 10
A focused DSA example for prefix sum with output and explanation.
Prefix Sum example 10
lesson.jsjavascript
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javascript8 linesWrap
Input
Terminal
SuccessReady.
Run code to see output here.
What this example teaches
Prefix Sum
Output
The function returns the correct result while keeping time and space tradeoffs visible.
Line-by-line explanation
- Line 1 sets up the Prefix Sum example: function uniqueValues(values) {.
- Line 2 adds one required part of the working pattern: const seen = new Set();.
- Line 3 exposes the output so you can verify the behavior: return values.filter((value) => {.
- Line 4 adds the decision or filter that controls the result: if (seen.has(value)) return false;.
- Line 5 adds one required part of the working pattern: seen.add(value);.
- Line 6 exposes the output so you can verify the behavior: return true;.
Why this example is useful
This example is useful because it isolates prefix sum without surrounding noise, so you can see the idea clearly.
Where it is used in real projects
Prefix Sum appears in real DSA work when a feature needs a clear pattern that can be reviewed and changed safely.
Beginner variation
Change one label, value or condition in the Prefix Sum example and run it again.
Advanced variation
Combine Prefix Sum with validation, error handling or reusable structure.