Missing Number

The list holds n distinct numbers taken from 0, 1, …, n, so exactly one number in that range is missing. Find it. (Hint: compare the expected total with the actual total.)

Implement missing_number(numbers).

Input

numbers: n distinct numbers from 0 to n.

Output

Return the missing number.

Contraintes

0 ≤ n ≤ 100,000

Exemples

Entrée :
numbers = [3, 0, 1]

Sortie attendue :
expected = 2

Entrée :
std::vector<long long> numbers = {3, 0, 1};

Sortie attendue :
long long expected = 2;

Entrée :
long[] numbers = new long[] {3, 0, 1};

Sortie attendue :
long expected = 2;

Entrée :
numbers = [0]

Sortie attendue :
expected = 1

Entrée :
std::vector<long long> numbers = {0};

Sortie attendue :
long long expected = 1;

Entrée :
long[] numbers = new long[] {0};

Sortie attendue :
long expected = 1;

Références

Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.

• GWU CS1111 Introduction to Software Development - lab sequence