leetcode

0 class FreqStack {

1 unordered_map<int, int> count;

2 vector<int> track[20001];

3 int maxi = 0;

4

5 public:

6 void push(int val) {

7 const int cnt = ++count[val];

8 track[cnt].push_back(val);

9 maxi = max(maxi, cnt);

10 }

11

12 int pop() {

13 const int res = track[maxi].back();

14 track[maxi].pop_back();

15 if (track[count[res]--].empty()) maxi--;

16 return res;

17 }

18 };