Question $4$: Given an array of n integers and their values between $1$ and n$.$ Write an algorithm

that outputs all values that are repeated $2$ or more times.

Example:

Input: array x values $\{7,4,8,7,3,9,3,8,7,8\}$

Output:

$73$

$83$

$32$

a$.$ What is its basic operation?

b$.$ What is the efficiency class of this algorithm?