oj.uz

Submission #595619

# Submission time Handle Problem Language Result Execution time Memory
595619 2022-07-13T21:52:59 Z definitelynotmee Event Hopping (BOI22_events) C++
30 / 100
 114 ms 14388 KB 
#include<bits/stdc++.h>
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
using namespace std;
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
template<typename T>
using matrix = vector<vector<T>>;
const int INF = 1<<30;

int main() {
    cin.tie(0)->sync_with_stdio(0);

    int n, q;
    cin >> n >> q;
    vector<pii> v(n);
    for(pii& i : v){
        cin >> i.ff >> i.ss;
        i.ff = INF-i.ff;
        i.ss = INF-i.ss;
        swap(i.ff,i.ss);
    }
    // cout << "----------\n";
    // for(pii i : v)
    //     cout << i.ff << ' ' << i.ss << '\n';
    // cout << "----------\n";
    vector<int>o(n);
    iota(all(o),0);
    sort(all(o),[&](int a, int b){
        return v[a] > v[b];
    });

    vector<int> jmp(n);
    vector<int> st;

    for(int i : o){
        int ini = 0, fim = st.size();
        while(ini!=fim){
            int m = (ini+fim)>>1;
            if(v[st[m]].ff <= v[i].ss)
                fim = m;
            else ini = m+1;
        }
        if(ini == st.size()){
            jmp[i] = i;
        } else jmp[i] = st[ini];
        
        while(!st.empty() && v[st.back()].ss <= v[i].ss)
            st.pop_back();
        st.push_back(i);
        // cout << i << ":\n";
        // for(int i : st)
        //     cout << i << ' ';
        // cout << '\n';
    }

    matrix<int> lift(20,vector<int>(n));
    for(int i = 0; i < n; i++){
        lift[0][i] = jmp[i]; 
        // cout << jmp[i] << ' ';
    }
    // cout << '\n';
    for(int i = 1; i < 20; i++){
        for(int j = 0; j < n; j++){
            lift[i][j] = lift[i-1][lift[i-1][j]];
        }
    }
    
    while(q--){
        int a, b;
        cin >> a >> b;
        a--, b--;
        swap(a,b);
        if(v[a] > v[b]){
            cout << "impossible\n";
            continue;
        }
        if(a == b){
            cout << 0 << '\n';
            continue;
        }
        if(v[a].ss >= v[b].ff){
            cout << 1 << '\n';
            continue;
        }
        int ct = 2;
        for(int i = 19; i >= 0; i--){
            if(v[lift[i][a]].ss < v[b].ff)
                ct+=1<<i, a = lift[i][a];
        }
        a = lift[0][a];
        if(v[a].ss >= v[b].ff){
            cout << ct << '\n';
        } else {
            cout << "impossible\n";
        }
    }

}

Compilation message

events.cpp: In function 'int main()':
events.cpp:46:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |         if(ini == st.size()){
      |            ~~~~^~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 61 ms 10836 KB Output is correct
3 Correct 78 ms 13832 KB Output is correct
4 Correct 112 ms 13788 KB Output is correct
5 Correct 93 ms 14020 KB Output is correct
6 Correct 83 ms 13836 KB Output is correct
7 Correct 98 ms 13872 KB Output is correct
8 Correct 100 ms 14388 KB Output is correct
9 Correct 101 ms 14264 KB Output is correct
10 Correct 85 ms 14264 KB Output is correct
11 Incorrect 92 ms 14152 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 28 ms 1308 KB Output is correct
20 Correct 28 ms 1268 KB Output is correct
21 Correct 30 ms 1552 KB Output is correct
22 Incorrect 23 ms 1532 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 0 ms 340 KB Output is correct
19 Correct 37 ms 10588 KB Output is correct
20 Correct 33 ms 10584 KB Output is correct
21 Correct 35 ms 10060 KB Output is correct
22 Incorrect 36 ms 10448 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 60 ms 10856 KB Output is correct
2 Correct 83 ms 13880 KB Output is correct
3 Correct 114 ms 13760 KB Output is correct
4 Correct 94 ms 14256 KB Output is correct
5 Correct 81 ms 14148 KB Output is correct
6 Correct 87 ms 13984 KB Output is correct
7 Correct 80 ms 14092 KB Output is correct
8 Correct 83 ms 14148 KB Output is correct
9 Correct 36 ms 12460 KB Output is correct
10 Correct 80 ms 13676 KB Output is correct
11 Correct 74 ms 13376 KB Output is correct
12 Correct 72 ms 13584 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 61 ms 10836 KB Output is correct
3 Correct 78 ms 13832 KB Output is correct
4 Correct 112 ms 13788 KB Output is correct
5 Correct 93 ms 14020 KB Output is correct
6 Correct 83 ms 13836 KB Output is correct
7 Correct 98 ms 13872 KB Output is correct
8 Correct 100 ms 14388 KB Output is correct
9 Correct 101 ms 14264 KB Output is correct
10 Correct 85 ms 14264 KB Output is correct
11 Incorrect 92 ms 14152 KB Output isn't correct
12 Halted 0 ms 0 KB -