Submission #599135

#	Time	Username	Problem	Language	Result	Execution time	Memory
599135		Vanilla	Event Hopping (BOI22_events)	C++17	10 / 100	1586 ms	199472 KiB

events

#include <bits/stdc++.h>
using namespace std;
typedef long long int64;
const int maxn = 5e3 + 2;
struct nd {
    int x;
    int y;
    int idx;

    bool operator < (const nd& oth) const {
        return make_pair(x, y) < make_pair(oth.x, oth.y);
    }
} a [maxn];
int dist [maxn][maxn];
vector <int> ad [maxn];

void prec (int u, int x) {
    set <int> q;
    // queue <int> q;
    q.insert(u);
    dist[u][x] = 0;
    while (!q.empty()) {
        int u = *q.begin();
        q.erase(q.begin());
        for (int v: ad[u]){
            if (dist[u][x] + 1 < dist[v][x]) {
                dist[v][x] = dist[u][x] + 1;
                q.insert(v);
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    int n,q;
    cin >> n >> q;
    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++) dist[i][j] = 1e9;
        cin >> a[i].x >> a[i].y;
        a[i].idx = i;
    }
    cout << "\n";
    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++){
            if (i != j && a[j].x <= a[i].y && a[i].y <= a[j].y) {
                // cout << i << " " << j << "\n";
                ad[i].push_back(j);
            }
        }
    }
    // sort(a, a + n);
    for (int i = 0; i < n; i++){
        prec(i, i);
    }
    // for (int i = 0; i < n; i++){
    //     for (int j = 0; j < n; j++){
    //         cout << i << " " << j << " " << dist[j][i] << "\n";
    //     }
    // }
    while (q--){
        int x,y;
        cin >> x >> y;
        x--, y--;
        cout << (dist[y][x] == 1e9 ? "impossible": to_string(dist[y][x])) << "\n";
    }
    return 0;
}

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