Submission #1206625

#	Time	Username	Problem	Language	Result	Execution time	Memory
1206625		ocean	Infinite Race (EGOI24_infiniterace2)	C++17	100 / 100	24 ms	1864 KiB

Main

#include <iostream>
#include <vector>
#include <cstdlib>   // abs
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, Q;
    if (!(cin >> N >> Q)) return 0;

    vector<long long> lastOver(N, -1); // epoch of last "+p"
    long long laps = 0;                // also the current epoch id

    while (Q--) {
        int x;  cin >> x;
        int p = std::abs(x);           // 1 … N-1

        if (x > 0) {                   // "+p"  – Anika overtakes p
            if (lastOver[p] == laps) { // already did that this epoch → need lap
                ++laps;                // new epoch starts *before* this event
            }
            lastOver[p] = laps;        // mark that p has been passed in epoch
        }
        else {                         // "-p" – p overtakes Anika
            lastOver[p] = -1;          // reset: p is in front again
        }
    }
    cout << laps << '\n';
    return 0;
}

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