oj.uz

Submission #595620

# Submission time Handle Problem Language Result Execution time Memory
595620 2022-07-13T21:54:49 Z definitelynotmee Event Hopping (BOI22_events) C++
30 / 100
 118 ms 11332 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();
        if(st.empty() || v[st.back()].ff > v[i].ff)
            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 0 ms 212 KB Output is correct
2 Correct 69 ms 10788 KB Output is correct
3 Correct 81 ms 10808 KB Output is correct
4 Correct 118 ms 10808 KB Output is correct
5 Correct 96 ms 10840 KB Output is correct
6 Correct 99 ms 10788 KB Output is correct
7 Correct 91 ms 10836 KB Output is correct
8 Correct 96 ms 11332 KB Output is correct
9 Correct 104 ms 11280 KB Output is correct
10 Correct 89 ms 11172 KB Output is correct
11 Incorrect 118 ms 11020 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 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 1 ms 340 KB Output is correct
19 Correct 31 ms 1300 KB Output is correct
20 Correct 30 ms 1300 KB Output is correct
21 Correct 43 ms 1576 KB Output is correct
22 Incorrect 27 ms 1620 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 424 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 39 ms 10580 KB Output is correct
20 Correct 34 ms 10652 KB Output is correct
21 Correct 37 ms 10088 KB Output is correct
22 Incorrect 41 ms 10612 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 64 ms 10824 KB Output is correct
2 Correct 80 ms 10856 KB Output is correct
3 Correct 114 ms 10804 KB Output is correct
4 Correct 103 ms 11272 KB Output is correct
5 Correct 97 ms 11152 KB Output is correct
6 Correct 83 ms 10976 KB Output is correct
7 Correct 84 ms 10908 KB Output is correct
8 Correct 75 ms 11080 KB Output is correct
9 Correct 40 ms 10588 KB Output is correct
10 Correct 78 ms 10632 KB Output is correct
11 Correct 71 ms 10600 KB Output is correct
12 Correct 79 ms 10588 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 69 ms 10788 KB Output is correct
3 Correct 81 ms 10808 KB Output is correct
4 Correct 118 ms 10808 KB Output is correct
5 Correct 96 ms 10840 KB Output is correct
6 Correct 99 ms 10788 KB Output is correct
7 Correct 91 ms 10836 KB Output is correct
8 Correct 96 ms 11332 KB Output is correct
9 Correct 104 ms 11280 KB Output is correct
10 Correct 89 ms 11172 KB Output is correct
11 Incorrect 118 ms 11020 KB Output isn't correct
12 Halted 0 ms 0 KB -