Submission #1064435

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064435		Shadow1	Infinite Race (EGOI24_infiniterace2)	C++17	100 / 100	28 ms	4964 KiB

Main

// Programmer: Shadow1

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using str = string; // yay python!

#define i64 int64_t
#define show(x) cerr << (#x) << " = " << (x) << '\n';
#define output_vector(v) for(auto &x : v){cout << x << ' ';}cout << '\n';
#define output_pairvector(v) for(auto &x : v){cout << x.first << " " << x.second << '\n';}
#define vt vector
#define pq priority_queue
#define pb push_back
#define eb emplace_back
#define pii pair<int,int>
#define umap unordered_map
#define uset unordered_set
#define fir first
#define sec second
#define sz(x) ll(x.size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define int ll
#define discretize(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());

// T: O(n^3)
// M : O(n + k log n) 

void solve() {
	int n, q;
	cin >> n >> q;
	vector<int> cnt(n), last(n);
	vector<bool> ahead(n);
	int lap = 1;
	while(q--) {
		int x; cin >> x;
		if(x > 0) {
			lap += (last[x] == lap && ahead[x]);
			last[x] = lap;
			ahead[x] = true;
		} else {
			ahead[abs(x)] = false;
		}
	}
	cout << lap - 1 << '\n';
}
	


signed main() {
	// freopen("output.txt", "w", stdout);
	// freopen("input.txt", "r", stdin);
	ios::sync_with_stdio(false);
	cin.tie(NULL); 
	int T = 1;
	// cin >> T;

	while(T--)
		solve();
	return 0;
}

/* CHECK :
1. COMPARATOR FUNCTION MUST RETURN FALSE WHEN ARGUMENTS ARE EQUAL!!!
2. Overflow! Typecase int64_t on operations if varaibles are int
3. Check array bounds!!!
4. Check array indexing!!!
5. Edge cases. (N==1)!!!
*/

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