oj.uz

Submission #877660

# Submission time Handle Problem Language Result Execution time Memory
877660 2023-11-23T12:14:44 Z VMaksimoski008 Event Hopping (BOI22_events) C++14
10 / 100
 47 ms 4536 KB 
#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

void setIO() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

int n, q;
struct Event {
    int a, b, id;
    bool operator<(Event &e) {
        return a < e.a;
    }
};

vector<Event> read_input(int n) {
    vector<Event> v;
    set<int> s;

    for(int i=0; i<n; i++) {
        int a, b;
        cin >> a >> b;
        v.push_back(Event{a, b, i+1});
        s.insert(a); s.insert(b);
    }

    vector<int> comp(all(s));
    for(Event &e : v) {
        e.a = lower_bound(all(comp), e.a) - comp.begin();
        e.b = lower_bound(all(comp), e.b) - comp.begin();
    }

    sort(all(v));
    return v;
}

void solve_bfs() {
    vector<pii> v(n+1);

    for(int i=1; i<=n; i++) cin >> v[i].first >> v[i].second;

    vector<vector<int> > graph(n+1);
    for(int i=1; i<=n; i++) {
        for(int j=1; j<=n; j++) {
            if(i == j) continue;
            if(v[j].first <= v[i].second && v[i].second <= v[j].second)
                graph[i].push_back(j);
        }
    }

    auto bfs = [&](int a, int b) {
        vector<bool> vis(n+1);
        vector<int> dist(n+1, 0);
        queue<int> q;
        vis[a] = 1;
        q.push(a);

        while(!q.empty()) {
            int u = q.front();
            q.pop();

            if(u == b) return dist[b];

            for(int &v : graph[u]) {
                if(vis[v]) continue;
                dist[v] = dist[u] + 1;
                vis[v] = 1;
                q.push(v);
            }
        }

        return -1;
    };

    while(q--) {
        int a, b;
        cin >> a >> b;

        int ans = bfs(a, b);
        if(ans == -1) cout << "impossible\n";
        else cout << ans << '\n';
    }
}

void solve_tree() {
    
}

int32_t main() {
    setIO();

    cin >> n >> q;
    if(n <= 1000) solve_bfs();
    else solve_tree();

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Incorrect 0 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 5 ms 536 KB Output is correct
4 Correct 4 ms 348 KB Output is correct
5 Correct 4 ms 348 KB Output is correct
6 Correct 9 ms 1116 KB Output is correct
7 Correct 16 ms 2016 KB Output is correct
8 Correct 16 ms 3160 KB Output is correct
9 Correct 46 ms 4444 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 5 ms 536 KB Output is correct
4 Correct 4 ms 348 KB Output is correct
5 Correct 4 ms 348 KB Output is correct
6 Correct 9 ms 1116 KB Output is correct
7 Correct 16 ms 2016 KB Output is correct
8 Correct 16 ms 3160 KB Output is correct
9 Correct 46 ms 4444 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 344 KB Output is correct
12 Correct 5 ms 604 KB Output is correct
13 Correct 4 ms 348 KB Output is correct
14 Correct 4 ms 348 KB Output is correct
15 Correct 9 ms 1264 KB Output is correct
16 Correct 15 ms 2004 KB Output is correct
17 Correct 16 ms 3164 KB Output is correct
18 Correct 47 ms 4444 KB Output is correct
19 Incorrect 0 ms 348 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 5 ms 536 KB Output is correct
4 Correct 4 ms 348 KB Output is correct
5 Correct 4 ms 348 KB Output is correct
6 Correct 9 ms 1116 KB Output is correct
7 Correct 16 ms 2016 KB Output is correct
8 Correct 16 ms 3160 KB Output is correct
9 Correct 46 ms 4444 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 5 ms 348 KB Output is correct
13 Correct 4 ms 348 KB Output is correct
14 Correct 4 ms 348 KB Output is correct
15 Correct 9 ms 1092 KB Output is correct
16 Correct 15 ms 1884 KB Output is correct
17 Correct 16 ms 3160 KB Output is correct
18 Correct 46 ms 4536 KB Output is correct
19 Incorrect 0 ms 348 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Incorrect 0 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -