Codility---MissingInteger

Posted 2020-09-14 Hugh

Task description

Write a function:

class Solution { public int solution(int[] A); }

that, given a non-empty zero-indexed array A of N integers, returns the minimal positive integer (greater than 0) that does not occur in A.

For example, given:

A[0] = 1 A[1] = 3 A[2] = 6 A[3] = 4 A[4] = 1 A[5] = 2

the function should return 5.

Assume that:

• N is an integer within the range [1..100,000];
• each element of array A is an integer within the range [−2,147,483,648..2,147,483,647].

Complexity:

• expected worst-case time complexity is O(N);
• expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Elements of input arrays can be modified.

Solution

 

Programming language used: Java

Total time used: 13 minutes

Code: 12:04:26 UTC, java, final, score:  100

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// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        Arrays.sort(A);
        int j=1;
        for(int i=0; i<A.length; i++) {
            if(A[i] <= 0)
                continue;
            if(A[i] == j)
                j++;
            else if(A[i] > j)
                break;
        }
        return j;
    }
}