You have an array A with n JPEG images some of which are identical.

You can check if two objects are equal but you cannot compare them in any other way—i.e. you can check A[i] == A[j] and A[i] != A[j], but comparisons such as A[i] < A[j] are not meaningful.

The array A is said to have a majority element if strictly more than half of its elements are equal to each other.

Use divide and conquer to come up with an O(n logn ) algorithm to determine if A has a majority element.