Submission #1080265

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080265		wiwiho	Infinite Race (EGOI24_infiniterace2)	C++14	100 / 100	24 ms	2904 KiB

Main

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

#define iter(v) v.begin(), v.end()
#define pb emplace_back
#define ff first
#define ss second

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#ifdef zisk
void debug() { cerr << "\n"; }
template<class T, class ... U>
void debug(T a, U... b) {
	cerr << a << " ", debug(b...);
}
template<class T>
void pary(T l, T r){
	while (l != r) cerr << *l << " ", l++;
	cerr << "\n";
}
#else
#define debug(...) void()
#define pary(...) void()
#endif

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int n;
	cin >> n;

	vector<int> r(n + 1);
	vector<bool> back(n + 1);
	int cur = 0;

	auto is_back = [&](int x) {
		return r[x] == cur && back[x];
	};

	int q;
	cin >> q;
	while (q--) {
		int x;
		cin >> x;
		if (x > 0) {
			if (is_back(x)) cur++;
			r[x] = cur;
			back[x] = true;
		}
		else {
			back[-x] = false;
		}
	}
	cout << cur << "\n";

}

• Subtask 1: 29 / 29
• Subtask 2: 34 / 34
• Subtask 3: 22 / 22
• Subtask 4: 15 / 15