[leetcode] 5225. Maximum Equal Frequency

Posted 2021-03-26 fish1996

https://leetcode.com/problems/maximum-equal-frequency/

class Solution {
public:
    int maxEqualFreq(vector<int>& nums) {
        unordered_map<int, int> count;
        unordered_map<int, int> frequency;

        int n = nums.size();


        int res = 0;
        for (int i = 0;i < n; i++)
        {
            int old_count = count[nums[i]];
            if (frequency.find(old_count) != frequency.end())
            {
                frequency[old_count]--;
                if (frequency[old_count] == 0)
                {
                    frequency.erase(old_count);
                }
            }
            count[nums[i]]++;
            frequency[count[nums[i]]]++;

            if(frequency.size() == 1)
            {
                int num;
                int time;
                for (auto& data : frequency)
                {
                    num = data.first;
                    time = data.second;
                }
                if(num == 1 || time == 1) 
                {
                    res = max(res, i + 1);
                }
                
            }
            else if (frequency.size() == 2)
            {
                int max_num = INT_MIN;
                int min_num = INT_MAX;
                int max_time;
                int min_time;

                for (auto& data : frequency)
                {
                    if (data.first > max_num)
                    {
                        max_time = data.second;
                    }
                    if (data.first < min_num)
                    {
                        min_time = data.second;
                    }
                    max_num = max(data.first, max_num);
                    min_num = min(data.first, min_num);
                }
              //  cout << min_num << " " << min_time << " " << max_num << " " << max_time << endl;
                if (max_num == min_num + 1 && max_time == 1)
                {
                    res = max(res, i + 1);
                }
                if(min_num == 1 && min_time == 1)
                {
                    res = max(res, i + 1);
                }
            }
        }
        return res;
    }
};