You have 10 bags full of infinite coins. But one bag is full of fake coins, and you can’t remember which one. You know that a genuine coin weighs 1 gram, and a fake coin weighs 1.1 grams. How do you identify the bag containing forged coins in minimum readings?

You are given an arbitrary array ‘arr’ consisting of N non-negative integers, where every element appears thrice except one. You need to find the element that appears only once.