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Submission #1002242

# Submission time Handle Problem Language Result Execution time Memory
1002242 2024-06-19T11:19:45 Z Andrey Event Hopping (BOI22_events) C++14
10 / 100
 68 ms 22624 KB 
#include<bits/stdc++.h>
using namespace std;

vector<int> bruh(200001);
vector<int> wow(200001);
vector<pair<int,int>> seg(500001);

void build(int l, int r, int x) {
    if(l == r) {
        seg[x] = {wow[l],l};
        return;
    }
    int m = (l+r)/2;
    build(l,m,x*2);
    build(m+1,r,x*2+1);
    seg[x] = min(seg[x*2],seg[x*2+1]);
}

pair<int,int> calc(int l, int r, int x, int ql, int qr) {
    if(l == ql && r == qr) {
        return seg[x];
    }
    int m = (l+r)/2;
    if(qr <= m) {
        return calc(l,m,x*2,ql,qr);
    }
    else if(ql > m) {
        return calc(m+1,r,x*2+1,ql,qr);
    }
    else {
        return min(calc(l,m,x*2,ql,m),calc(m+1,r,x*2+1,m+1,qr));
    }
}

int apple[100001][17];
int banana[100001][17];

int main()
{
    ios_base::sync_with_stdio(NULL);
    cin.tie(NULL);
    cout.tie(NULL);
    int n,q,a,b;
    cin >> n >> q;
    vector<pair<pair<int,int>,int>> haha(n+1);
    for(int i = 1; i <= n; i++) {
        cin >> a >> b;
        haha[i] = {{b,a},i};
    }
    sort(haha.begin(),haha.end());
    vector<int> pos(n+1);
    for(int i = 1; i <= n; i++) {
        pos[haha[i].second] = i;
        bruh[i] = haha[i].first.first;
        wow[i] = haha[i].first.second;
    }
    priority_queue<pair<int,int>> idk;
    for(int i = n; i >= 1; i--) {
        while(!idk.empty() && idk.top().second > bruh[i]) {
            idk.pop();
        }
        if(idk.empty()) {
            apple[i][0] = -1;
        }
        else {
            apple[i][0] = idk.top().first;
        }
        idk.push({i,wow[i]});
    }
    build(1,n,1);
    for(int i = 1; i <= n; i++) {
        int l,r;
        if(i == 1 || bruh[i-1] < wow[i]) {
            banana[i][0] = -1;
        }
        else{ 
            l = 1,r = i-1;
            while(l < r) {
                int m = (l+r)/2;
                if(bruh[l] < wow[i]) {
                    l = m+1;
                }
                else {
                    r = m;
                }
            }
            banana[i][0] = calc(1,n,1,l,i-1).second;
        }
    }
    for(int i = 1; i < 17; i++) {
        for(int j = 1; j <= n; j++) {
            if(apple[j][i-1] == -1) {
                apple[j][i] = -1;
            }
            else {
                apple[j][i] = apple[apple[j][i-1]][i-1];
            }
            if(banana[j][i-1] == -1) {
                banana[j][i] = -1;
            }
            else {
                banana[j][i] = banana[banana[j][i-1]][i-1];
            }
        }
    }
    for(int i = 0; i < q; i++) {
        cin >> a >> b;
        a = pos[a];
        b = pos[b];
        if(a > b) {
            if(bruh[a] == bruh[b]) {
                cout << 1 << "\n";
            }
            else {
                cout << "impossible\n";
            }
            continue;
        }
        int ans = 0;
        for(int j = 16; j >= 0; j--) {
            if(apple[a][j] == -1 || apple[a][j] > b) {
                continue;
            }
            ans+=(1 << j);
            a = apple[a][j];
        }
        if(a == b) {
            cout << ans << "\n";
            continue;
        }
        for(int j = 16; j >= 0; j--) {
            if(banana[b][j] == -1 || banana[b][j] < a) {
                continue;
            }
            ans+=(1 << j);
            b = banana[b][j];
        }
        if(b < a) {
            cout << 1/0 << endl;
        }
        if(b == a) {
            cout << ans << "\n";
        }
        else if(wow[b] <= bruh[a]) {
            cout << ans+1 << "\n";
        }
        else {
            cout << "impossible\n";
        }
    }
    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:139:22: warning: division by zero [-Wdiv-by-zero]
  139 |             cout << 1/0 << endl;
      |                     ~^~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7772 KB Output is correct
2 Correct 68 ms 21192 KB Output is correct
3 Correct 55 ms 21404 KB Output is correct
4 Correct 57 ms 21328 KB Output is correct
5 Correct 54 ms 21328 KB Output is correct
6 Correct 56 ms 21416 KB Output is correct
7 Correct 63 ms 21332 KB Output is correct
8 Correct 43 ms 22624 KB Output is correct
9 Correct 42 ms 21712 KB Output is correct
10 Correct 64 ms 21576 KB Output is correct
11 Correct 61 ms 21584 KB Output is correct
12 Correct 52 ms 21720 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7768 KB Output is correct
2 Correct 2 ms 7772 KB Output is correct
3 Correct 2 ms 8028 KB Output is correct
4 Correct 2 ms 8028 KB Output is correct
5 Correct 2 ms 8028 KB Output is correct
6 Incorrect 2 ms 8028 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7768 KB Output is correct
2 Correct 2 ms 7772 KB Output is correct
3 Correct 2 ms 8028 KB Output is correct
4 Correct 2 ms 8028 KB Output is correct
5 Correct 2 ms 8028 KB Output is correct
6 Incorrect 2 ms 8028 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7768 KB Output is correct
2 Correct 2 ms 7772 KB Output is correct
3 Correct 2 ms 8028 KB Output is correct
4 Correct 2 ms 8028 KB Output is correct
5 Correct 2 ms 8028 KB Output is correct
6 Incorrect 2 ms 8028 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 21208 KB Output is correct
2 Correct 54 ms 21332 KB Output is correct
3 Correct 64 ms 21332 KB Output is correct
4 Correct 43 ms 21728 KB Output is correct
5 Correct 64 ms 21584 KB Output is correct
6 Incorrect 64 ms 21324 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 7772 KB Output is correct
2 Correct 68 ms 21192 KB Output is correct
3 Correct 55 ms 21404 KB Output is correct
4 Correct 57 ms 21328 KB Output is correct
5 Correct 54 ms 21328 KB Output is correct
6 Correct 56 ms 21416 KB Output is correct
7 Correct 63 ms 21332 KB Output is correct
8 Correct 43 ms 22624 KB Output is correct
9 Correct 42 ms 21712 KB Output is correct
10 Correct 64 ms 21576 KB Output is correct
11 Correct 61 ms 21584 KB Output is correct
12 Correct 52 ms 21720 KB Output is correct
13 Correct 2 ms 7768 KB Output is correct
14 Correct 2 ms 7772 KB Output is correct
15 Correct 2 ms 8028 KB Output is correct
16 Correct 2 ms 8028 KB Output is correct
17 Correct 2 ms 8028 KB Output is correct
18 Incorrect 2 ms 8028 KB Output isn't correct
19 Halted 0 ms 0 KB -