/**
* @param {number[]} nums
* @return {number}
*/
var majorityElement = function(nums) {
var count = 1;
var m = nums[0];
for (var i = 1; i < nums.length; ++i) {
if (nums[i] == m) {
count++;
} else if (count == 0) {
m = nums[i];
count = 1;
} else {
count--;
}
}
return m;
};
摩尔投票算法 wiki