Submission #1094710

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094710		crafticat	Event Hopping (BOI22_events)	C++17	0 / 100	1587 ms	3392 KiB

events

#include "bits/stdc++.h"

using namespace std;
template<typename T>
using V = vector<T>;
using vi = V<int>;
using pi = pair<int,int>;
#define f first
#define s second

#define F0R(i, n) for(int i = 0; i < n;i++)
#define FOR(i,a, n) for(int i = a; i < n;i++)
#define pb push_back
#define all(x) begin(x), end(x)
#define each(x, y) for(auto &x : y)
constexpr int INF = 1e9 + 2;

pi binarySearch(V<pi> &stack, int point) {
    auto it = std::upper_bound(stack.begin(), stack.end(), make_pair(point,INF)); // Point to before or at point
    if (it == stack.begin()) return {0,0};
    it--;
    return {it - stack.begin() + 1, it->s};
}

int getImp(V<pi> &stack) {
    return (stack.empty() ? 0 : stack.back().s);
}
#define ckmax(a,b) a = max(a,b)

int main() {
    int n, q; cin >> n >> q;

    V<pi> edges;

    F0R(i, n) {
        int a, b; cin >> a >> b;
        edges.pb({a,b});
    }
    F0R(i, q) {
        int a, b; cin >> a >> b;
        a--;
        b--;

        int point = edges[a].s;
        int ans = 0;

        while (point < edges[b].f) {
            int bestNext = point;
            ans++;
            F0R(j, n) {
                if (edges[j].f <= point) ckmax(bestNext, edges[j].s);
            }
            if (bestNext == point) break;
            point = bestNext;
        }
        if (a == b) {
            cout << "0\n";
            continue;
        }
        if (point < edges[b].f || point > edges[b].s) {
            cout << "impossible\n";
            continue;
        }

        cout << ans + 1 << "\n";
    }


    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30