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easy
Find the missing element in a given permutation.
Task Score
100%
Correctness
100%
Performance
100%
Task description

An array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing.

Your goal is to find that missing element.

Write a function:

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

that, given an array A, returns the value of the missing element.

For example, given array A such that:

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

the function should return 4, as it is the missing element.

Assume that:

  • N is an integer within the range [0..100,000];
  • the elements of A are all distinct;
  • each element of array A is an integer within the range [1..(N + 1)].

Complexity:

  • expected worst-case time complexity is O(N);
  • expected worst-case space complexity is O(1) (not counting the storage required for input arguments).
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Solution
Programming language used Java
Total time used 2 minutes
Effective time used 2 minutes
Notes
not defined yet
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