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MediumPro challengeJavaScriptTypeScript

useCallback Hook

ReactHooksMemoization

Implement useCallback(fn, deps) returning the same function reference
across renders unless deps change.

solve(steps) returns how many unique function references were produced.
Each step provides deps; useCallback is called once per step.

Sample tests

Test #1No steps
Input: [[]]
Output: 0
Test #2Same deps → 1 unique ref
Input: [[{"deps":[1]},{"deps":[1]},{"deps":[1]}]]
Output: 1
Test #3Different deps → 2 refs
Input: [[{"deps":[1]},{"deps":[2]}]]
Output: 2
Test #4Two unique dep groups
Input: [[{"deps":[1,2]},{"deps":[1,2]},{"deps":[1,3]},{"deps":[1,3]}]]
Output: 2
Test #5Empty deps array
Input: [[{"deps":[]},{"deps":[]}]]
Output: 1
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