First Missing Positive

hard

Acceptance: 38%

Arrays

Given an unsorted array of integers, find the smallest positive integer that does not appear in the array. Your solution must achieve linear time complexity and use only constant additional space beyond the input array itself.

Examples

Example 1:

Input:nums = [5,3,1]

Output:2

Explanation: The positive integers present are 1, 3, 5. The smallest absent positive integer is 2.

Example 2:

Input:nums = [1,2,3,4]

Output:5

Explanation: All integers from 1 through 4 are present, so the answer is 5.

Hints

1234567

import java.util.*;

public class Main {
    public static void main(String[] args) {
        // Write your solution here
    }
}

import java.util.*;

public class Main {
    public static void main(String[] args) {
        // Write your solution here
    }
}

First Missing Positive

Examples

Hints

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