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Submission #599863

# Submission time Handle Problem Language Result Execution time Memory
599863 2022-07-20T03:51:19 Z JooDdae Event Hopping (BOI22_events) C++17
30 / 100
 118 ms 19156 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int n, q, sp[100100][20], mn[100100][20], R[100100], rev[100100];
array<int, 3> a[100100];

int find(int a, int b){
    int k = 31 - __builtin_clz(b - a);
    return min(mn[a][k], mn[b-(1<<k)+1][k]);
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> q;
    for(int i=1;i<=n;i++) cin >> a[i][1] >> a[i][0], a[i][2] = i;
    sort(a+1, a+1+n);

    for(int i=n;i>=1;i--){
        auto [e, s, id] = a[i];

        R[i] = a[i+1][0] == e ? R[i+1] : i;
        rev[id] = i;
        mn[i][0] = lower_bound(a+1, a+1+n, array<int, 3>({s, 0, 0})) - a;
    }

    for(int j=1;j<20;j++) for(int i=1;i<=n;i++) if(i+(1<<j)-1 <= n) mn[i][j] = min(mn[i][j-1], mn[i+(1<<j-1)][j-1]);

    for(int i=1;i<=n;i++) sp[i][0] = find(i, R[i]);
    for(int j=1;j<20;j++) for(int i=1;i<=n;i++) sp[i][j] = min(sp[i][j-1], sp[sp[i][j-1]][j-1]);


    while(q--){
        int a, b; cin >> a >> b;
        a = rev[a], b = rev[b];

        if(R[b] < a) {
            cout << "impossible\n";
        } else if(a == b) {
            cout << "0\n";
        } else {
            int ans = 0;

            for(int i=19;i>=0;i--) if(sp[b][i] > a) b = sp[b][i], ans += 1 << i;
            ans++, b = sp[b][0];

            if(a < b) cout << "impossible\n";
            else cout << ans << "\n";
        }
    }
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:27:106: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   27 |     for(int j=1;j<20;j++) for(int i=1;i<=n;i++) if(i+(1<<j)-1 <= n) mn[i][j] = min(mn[i][j-1], mn[i+(1<<j-1)][j-1]);
      |                                                                                                         ~^~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 79 ms 18632 KB Output is correct
3 Correct 80 ms 18648 KB Output is correct
4 Correct 93 ms 18640 KB Output is correct
5 Correct 89 ms 18656 KB Output is correct
6 Correct 80 ms 18632 KB Output is correct
7 Correct 90 ms 18768 KB Output is correct
8 Correct 100 ms 19072 KB Output is correct
9 Correct 85 ms 19156 KB Output is correct
10 Correct 97 ms 19008 KB Output is correct
11 Correct 118 ms 19012 KB Output is correct
12 Correct 73 ms 19124 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 484 KB Output is correct
5 Correct 1 ms 528 KB Output is correct
6 Incorrect 1 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 484 KB Output is correct
5 Correct 1 ms 528 KB Output is correct
6 Incorrect 1 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 484 KB Output is correct
5 Correct 1 ms 528 KB Output is correct
6 Incorrect 1 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 92 ms 18628 KB Output is correct
2 Correct 98 ms 18592 KB Output is correct
3 Correct 86 ms 18636 KB Output is correct
4 Correct 79 ms 19148 KB Output is correct
5 Correct 118 ms 18976 KB Output is correct
6 Correct 98 ms 18736 KB Output is correct
7 Correct 99 ms 18760 KB Output is correct
8 Correct 86 ms 18860 KB Output is correct
9 Correct 54 ms 17976 KB Output is correct
10 Correct 105 ms 18448 KB Output is correct
11 Correct 87 ms 18184 KB Output is correct
12 Correct 78 ms 18420 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 79 ms 18632 KB Output is correct
3 Correct 80 ms 18648 KB Output is correct
4 Correct 93 ms 18640 KB Output is correct
5 Correct 89 ms 18656 KB Output is correct
6 Correct 80 ms 18632 KB Output is correct
7 Correct 90 ms 18768 KB Output is correct
8 Correct 100 ms 19072 KB Output is correct
9 Correct 85 ms 19156 KB Output is correct
10 Correct 97 ms 19008 KB Output is correct
11 Correct 118 ms 19012 KB Output is correct
12 Correct 73 ms 19124 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 484 KB Output is correct
17 Correct 1 ms 528 KB Output is correct
18 Incorrect 1 ms 468 KB Output isn't correct
19 Halted 0 ms 0 KB -