Implement plurality and majority voting

You are given an array votes of length n, where each element is a candidate identifier (string or integer).

Implement two voting systems:

1) Plurality vote

Return the candidate with the highest number of votes.

• If multiple candidates are tied for the highest count, return the lexicographically smallest candidate (if identifiers are strings) or the smallest numeric id (if integers).

2) Majority vote (Boyer–Moore)

Return the candidate who has strictly more than n/2 votes.

• If no such candidate exists, return null (or None).
• This must be done in O(n) time and O(1) extra space (aside from the input), i.e., using the Boyer–Moore majority vote technique.

Input/Output

• Input: votes: List[Candidate]
• Output:
  • pluralityWinner(votes) -> Candidate
  • majorityWinner(votes) -> Candidate | null

Constraints

• 1 <= n <= 10^6
• Candidate identifiers are comparable for tie-breaking.

Examples

1. votes = ["A", "B", "A", "C", "B", "A"]

   • plurality winner: "A" (3 votes)
   • majority winner: null (3 is not > 6/2)

2. votes = [2, 2, 1, 2]

   • plurality winner: 2
   • majority winner: 2 (3 > 4/2)