数组中个数超过一半的数（包含不存在的情况）.txt

class Solution {
public:
    /*int MoreThanHalfNum_Solution(vector<int> numbers) {//抵消计数法，然后统计current的个数
        int countnum = 0;
        int current = 0;
        for(int i=0;i<numbers.size();++i)
        {
            if(countnum == 0)
            {
                current=numbers[i];
                countnum++;
            }
            else
            {
               if(current!=numbers[i])countnum--;
               else
                   countnum++;
            }
        }
        
        countnum = 0;
        for(int i=0;i<numbers.size();++i)
        {
            if(current==numbers[i])
                countnum++;
        }
        if(countnum>(numbers.size()/2))
        {
            return current;
            
        }
        else
        {
            return  0;
        }
    }*/
    
    int MoreThanHalfNum_Solution(vector<int> numbers) {//利用map保存一下个数即可
        map<int,int> hash;
        for(int i=0;i<numbers.size();++i)
        hash[numbers[i]]++;
        for(int i=0;i<numbers.size();++i)
        {
            if(hash[numbers[i]]>(numbers.size()/2))
                return numbers[i];
        }
        return 0;    
    }
};