oj.uz

Submission #1002166

# Submission time Handle Problem Language Result Execution time Memory
1002166 2024-06-19T10:38:32 Z Andrey Event Hopping (BOI22_events) C++14
20 / 100
 74 ms 25804 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[x],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) {
            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 || wow[banana[b][j]] <= bruh[a]) {
                continue;
            }
            ans+=(1 << j);
            b = banana[b][j];
        }
        if(banana[b][0] == -1 || banana[b][0] > bruh[a]) {
            cout << "impossible\n";
        }
        else {
            cout << ans+1 << "\n";
        }
    }
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5724 KB Output is correct
2 Correct 58 ms 24532 KB Output is correct
3 Correct 56 ms 24444 KB Output is correct
4 Correct 63 ms 24504 KB Output is correct
5 Correct 62 ms 24432 KB Output is correct
6 Correct 63 ms 24404 KB Output is correct
7 Correct 59 ms 24524 KB Output is correct
8 Correct 47 ms 25804 KB Output is correct
9 Correct 47 ms 24916 KB Output is correct
10 Correct 70 ms 24656 KB Output is correct
11 Incorrect 70 ms 24916 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5724 KB Output is correct
2 Correct 2 ms 5724 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 3 ms 5992 KB Output is correct
5 Incorrect 2 ms 6128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5724 KB Output is correct
2 Correct 2 ms 5724 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 3 ms 5992 KB Output is correct
5 Incorrect 2 ms 6128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5724 KB Output is correct
2 Correct 2 ms 5724 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 3 ms 5992 KB Output is correct
5 Incorrect 2 ms 6128 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 58 ms 24400 KB Output is correct
2 Correct 60 ms 24460 KB Output is correct
3 Correct 62 ms 24268 KB Output is correct
4 Correct 47 ms 24908 KB Output is correct
5 Correct 70 ms 24656 KB Output is correct
6 Correct 68 ms 24432 KB Output is correct
7 Correct 72 ms 24396 KB Output is correct
8 Correct 70 ms 24660 KB Output is correct
9 Correct 41 ms 23500 KB Output is correct
10 Correct 65 ms 24144 KB Output is correct
11 Correct 65 ms 24276 KB Output is correct
12 Correct 74 ms 24144 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5724 KB Output is correct
2 Correct 58 ms 24532 KB Output is correct
3 Correct 56 ms 24444 KB Output is correct
4 Correct 63 ms 24504 KB Output is correct
5 Correct 62 ms 24432 KB Output is correct
6 Correct 63 ms 24404 KB Output is correct
7 Correct 59 ms 24524 KB Output is correct
8 Correct 47 ms 25804 KB Output is correct
9 Correct 47 ms 24916 KB Output is correct
10 Correct 70 ms 24656 KB Output is correct
11 Incorrect 70 ms 24916 KB Output isn't correct
12 Halted 0 ms 0 KB -