數組-哈希表-面試題39. 數組中出現次數超過一半的數字

class Solution {
    public int majorityElement(int[] nums) {
        Arrays.sort(nums);
        return nums[nums.length/2];
    }
}

 法二：哈希表 c++

class Solution {
public:
    int majorityElement(vector<int>& nums) {
        unordered_map<int,int>mp;
        for(auto it:nums){
            mp[it]++;
            if(mp[it]>nums.size()/2) return it;
        }
        return 0;
    }
};