Leetcode-895 Maximum Frequency Stack(最大频率堆栈)

class FreqStack
{
    public:
        unordered_map<int,int> hash;
        vector<int> stk;
        int max_times;
        int times_table[10001];
        FreqStack()
        {
            memset(times_table,0,sizeof(times_table));
            max_times = 0;
        }

        void push(int x)
        {
            stk.push_back(x);

            auto ptr_to_hash = hash.find(x);
            if(ptr_to_hash==hash.end())
            {
                hash.insert(make_pair(x,1));
                times_table[1] ++;
                max_times = max(1,max_times);
            }
            else
            {
                times_table[ptr_to_hash->second] --;
                ptr_to_hash->second += 1;
                times_table[ptr_to_hash->second] ++;
                max_times = max(ptr_to_hash->second,max_times);
            //    cout << x << " " << max_times << endl;
            }
        }

        int pop()
        {
            for(int i = stk.size()-1;i >= 0;i --)
            {
                auto ptr_to_hash = hash.find(stk[i]);
                if(ptr_to_hash->second==max_times)
                {
                    int result = stk[i];
                    stk.erase(stk.begin()+i);
                    times_table[ptr_to_hash->second] --;
                    ptr_to_hash->second -= 1;
                    times_table[ptr_to_hash->second] ++;
                    if(!times_table[max_times])
                    {
                        max_times --;
                    }
                    return result;
                }
            }
            return max_times;
        }
};