169. Majority Element

Given an array nums of size n, return the majority element: the value that appears more than ⌊n / 2⌋ times. It always exists.

Keep a candidate and a counter. Matching values vote for it, others vote against. When the counter hits zero, pick the current value. The majority survives all cancellations.

1function majorityElement(nums: number[]): number {
2  let candidate = 0, count = 0;
3  for (const x of nums) {
4    if (count === 0) candidate = x;
5    count += x === candidate ? 1 : -1;
6  }
7  return candidate;
8}