Find the smallest positive integer that does not occur in a given sequence.
- Difficulty Level: Medium
- Question URL: https://app.codility.com/programmers/lessons/4-counting_elements/missing_integer/
- Time Complexity:
Solution:
Solution to Codility's Missing Integer problem which is from the Codility Lesson 4: Counting Elements and, is solved in Java 8 with 100% performance and correctness scores. The goal here is to find the smallest positive integer that does not occur in a given sequence. You can find the question of this MissingInteger problem in the Codility website.
package Codility.Lesson4;
import java.util.*;
public class MissingInteger {
public static void main(String[] args) {
// TODO Auto-generated method stub
int input[] = { 3, 4, 4, 6, 1, 4, 4 };
int result = solution(input);
System.out.println(result);
}
public static int solution(int[] A) {
// write your code in Java SE 8
Arrays.sort(A);
int counter = 0;
int previous = 0;
for (int i = 0; i < A.length; i++) {
if (A[i] > 0) {
if (previous != A[i]) {
counter++;
if (A[i] != counter) {
return counter;
}
}
previous = counter;
}
}
if (counter >= 0) {
return counter + 1;
}
return 1;
}
}