백준 1700번 : 멀티탭 스케줄링 - 그리디 C++

https://www.acmicpc.net/problem/1700

1700번: 멀티탭 스케줄링

#include <bits/stdc++.h>
#include <unordered_set>
using namespace std;



int n, k;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> k;

	vector<int> v;
	for (int i = 0; i < k; i++) {
		int tmp;
		cin >> tmp;
		v.push_back(tmp);
	}

	unordered_set<int> set;

	int ans = 0;
	for (int i = 0; i < k; i++) {
		int tmp = v[i];

		if (set.size() < n) {
			set.insert(tmp);
		}
		else if(set.size()==n) {
			if (set.count(tmp)) {
				continue;
			}
			else {
				map<int, int> m;

				for (auto x : set) {
					m[x] = 1000;
				}

				for (int j = i + 1; j < k; j++) {
					if (set.count(v[j])) {
						m[v[j]] = min(m[v[j]], j);
					}
				}

				int maxx = 0;
				int max_id = -1;

				for (auto x : set) {
					if (maxx < m[x]) {
						maxx = m[x];
						max_id = x;
					}
				}
				set.erase(max_id);
				set.insert(tmp);
				
				ans++;
			}
		}

	}

	cout << ans << '\n';


	return 0;
}