| 3 | list<int> q; |
| 4 | int sz; |
| 5 | void insert(int x) |
| 6 | { |
| 7 | |
| 8 | // if not present |
| 9 | if (mp.find(x) == mp.end()) |
| 10 | { |
| 11 | if (q.size() == sz) |
| 12 | { |
| 13 | int last = q.back(); |
| 14 | q.pop_back(); |
| 15 | mp.erase(last); |
| 16 | } |
| 17 | } |
| 18 | // if present |
| 19 | else |
| 20 | mp.erase(x); |
| 21 | |
| 22 | q.push_front(x); |
| 23 | mp[x] = q.begin(); |
| 24 | } |
| 25 | |
| 26 | void display() |
| 27 | { |