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Submission #653573

# Submission time Handle Problem Language Result Execution time Memory
653573 2022-10-27T10:28:39 Z AlperenT Event Hopping (BOI22_events) C++17
10 / 100
 95 ms 14500 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

int n, q, where[N], pref[N], tin[N], tout[N], tim, depth[N];

struct Event{
    int l, r;

    bool operator < (const Event &sc) const{
        if(r == sc.r) return l < sc.l;
        else return r < sc.r;
    }
};

Event arr[N];

vector<pair<Event, int>> v;

vector<int> tree[N];

bool vis[N];

void dfs(int v, int p){
    tin[v] = ++tim;
    depth[v] = depth[p] + 1;
    vis[v] = true;

    for(auto e : tree[v]){
        if(e != p) dfs(e, v);
    }

    tout[v] = ++tim;
}

bool isanc(int a, int b){
    return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}

bool canmove(Event a, Event b){
    return b.l <= a.r && a.r <= b.r;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);

    cin >> n >> q;

    for(int i = 1; i <= n; i++) cin >> arr[i].l >> arr[i].r;

    for(int i = 1; i <= n; i++) v.push_back({arr[i], i});

    sort(v.begin(), v.end());

    set<pair<int, int>> st;

    for(auto p : v){
        while(!st.empty() && prev(st.end())->first >= p.first.l){
            tree[p.second].push_back(prev(st.end())->second);

            st.erase(prev(st.end()));
        }

        st.insert({p.first.r, p.second});
    }

    for(int i = n - 1; i >= 0; i--){
        if(!vis[v[i].second]){
            dfs(v[i].second, 0);
        }
    }

    while(q--){
        int s, e;

        cin >> s >> e;

        if(isanc(e, s)) cout << depth[s] - depth[e] << "\n";
        else{
            if(canmove(arr[s], arr[e])) cout << 1 << "\n";
            else cout << "impossible\n";
        }
    }
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 95 ms 14248 KB Output is correct
3 Correct 83 ms 14272 KB Output is correct
4 Correct 73 ms 14256 KB Output is correct
5 Correct 65 ms 13496 KB Output is correct
6 Correct 73 ms 12832 KB Output is correct
7 Correct 70 ms 12660 KB Output is correct
8 Correct 68 ms 11608 KB Output is correct
9 Correct 68 ms 11696 KB Output is correct
10 Correct 68 ms 12260 KB Output is correct
11 Correct 67 ms 10572 KB Output is correct
12 Correct 59 ms 11088 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2644 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2644 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2644 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 73 ms 14304 KB Output is correct
2 Correct 69 ms 14272 KB Output is correct
3 Correct 86 ms 14312 KB Output is correct
4 Correct 70 ms 11596 KB Output is correct
5 Correct 74 ms 12356 KB Output is correct
6 Incorrect 73 ms 14500 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 95 ms 14248 KB Output is correct
3 Correct 83 ms 14272 KB Output is correct
4 Correct 73 ms 14256 KB Output is correct
5 Correct 65 ms 13496 KB Output is correct
6 Correct 73 ms 12832 KB Output is correct
7 Correct 70 ms 12660 KB Output is correct
8 Correct 68 ms 11608 KB Output is correct
9 Correct 68 ms 11696 KB Output is correct
10 Correct 68 ms 12260 KB Output is correct
11 Correct 67 ms 10572 KB Output is correct
12 Correct 59 ms 11088 KB Output is correct
13 Incorrect 2 ms 2644 KB Output isn't correct
14 Halted 0 ms 0 KB -