Submission #1291430

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291430		nishu	Teleporters (IOI08_teleporters)	C++17	Compilation error	0 ms	0 KiB

teleporters

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
using namespace std;

struct Teleporter {
    int a, b;
};

int main() {
    int N, M;
    cin >> N >> M;
    vector<Teleporter> teleporters(N);
    set<int> endpoints;

    for (int i = 0; i < N; ++i) {
        cin >> teleporters[i].a >> teleporters[i].b;
        endpoints.insert(teleporters[i].a);
        endpoints.insert(teleporters[i].b);
    }

    // Add new teleporters (simple version: just place them at unused unique positions)
    int current = 1;
    while (M > 0) {
        while (endpoints.count(current)) ++current;
        int a = current++;
        while (endpoints.count(current)) ++current;
        int b = current++;
        teleporters.push_back({a, b});
        endpoints.insert(a);
        endpoints.insert(b);
        --M;
    }

    // Simulate journey from 0 eastward: sort endpoints
    vector<int> events(endpoints.begin(), endpoints.end());
    sort(events.begin(), events.end());

    // Map each endpoint to its pair
    map<int, int> tele_map;
    for (auto &t : teleporters) {
        tele_map[t.a] = t.b;
        tele_map[t.b] = t.a;
    }

    int position = 0;
    int points = 0;
    while (position < events.back()) {
        auto it = upper_bound(events.begin(), events.end(), position);
        if (it == events.end()) break;
        int next = *it;

        // If next is a teleporter endpoint, use it
        if (tele_map.count(next)) {
            position = tele_map[next];
            points++;
        } else {
            position = next;
        }
    }

    cout << "Total points: " << points << endl;
    return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:41:5: error: 'map' was not declared in this scope
   41 |     map<int, int> tele_map;
      |     ^~~
teleporters.cpp:5:1: note: 'std::map' is defined in header '<map>'; did you forget to '#include <map>'?
    4 | #include <set>
  +++ |+#include <map>
    5 | using namespace std;
teleporters.cpp:41:9: error: expected primary-expression before 'int'
   41 |     map<int, int> tele_map;
      |         ^~~
teleporters.cpp:43:9: error: 'tele_map' was not declared in this scope
   43 |         tele_map[t.a] = t.b;
      |         ^~~~~~~~
teleporters.cpp:55:13: error: 'tele_map' was not declared in this scope
   55 |         if (tele_map.count(next)) {
      |             ^~~~~~~~