ORIGINAL CODING QUESTION
First positive inventory gap
Return the smallest positive integer absent from the supplied values.
Original exercise · hard. Editorial role relevance does not imply a company has asked this question.
Input and output
n, then n integer values. Print one integer as described.
Constraints
1 ≤ n ≤ 200; -100 ≤ value ≤ 100. Inputs contain exactly the stated values.
Example 1
Input
4 3 4 -1 1
Output
2
The first absent positive is 2.
Example 2
Input
3 1 2 3
Output
4
The first absent positive is 4.
Explain your approach
Explain your time and auxiliary space complexity. Which input makes your algorithm work hardest?
Private grading inputs, expected outputs and canonical reference implementations are withheld. Authored expected outputs were cross-checked with independent reference oracles; compiler/runtime behavior still needs a verified execution provider.
Hint 1
Only values 1 through n+1 can determine the answer.
Hint 2
Map a valid positive value to its corresponding index.
Hint 3
After placing or marking relevant values, scan for the first absent position.
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