You have been given an integer array/list(ARR) of size N which contains numbers from 0 to (N - 2). Each number is present at least once. That is, if N = 5, the array/list constitutes values ranging ...

Solution 1 : Our first solution is very simple. All we are doing here is to loop over an array and comparing each element to every other element. For doing this, we are using two loops, inner loop, ...