Linear Time Voting Algorithm. I don't get it

Question

As I was reading this (Find the most common entry in an array), the Boyer and Moore\'s Linear Time Voting Algorithm was suggested.

If you follow the link to the si

Answer 1

Small but an important addition to the other explanations. Moore's Voting algorithm has 2 parts -

1. first part of running Moore's Voting algorithm only gives you a candidate for the majority element. Notice the word "candidate" here.

2. In the second part, we need to iterate over the array once again to determine if this candidate occurs maximum number of times (i.e. greater than size/2 times).

First iteration is to find the candidate & second iteration is to check if this element occurs majority of times in the given array.

So time complexity is: O(n) + O(n) ≈ O(n)