[Codility] Lesson 3. Time Complexity - PermMissingElem

1부터 N개의 서로 다른 정수로 이루어진 배열에서 누락된 하나의 요소 찾기

 

import java.util.Arrays;

class Solution {
  public int solution(int[] A) {
    Arrays.sort(A);
    for (int i = 0; i < A.length; i++) {
      if (i + 1 != A[i]) {
      	return i + 1;
      }
    }
    return A.length + 1;
  }
}