oj.uz

Submission #1098185

# Submission time Handle Problem Language Result Execution time Memory
1098185 2024-10-09T06:04:44 Z rifat414141 Event Hopping (BOI22_events) C++17
30 / 100
 107 ms 30792 KB 
#include <bits/stdc++.h>
#define int long long int
#define endl '\n'
using namespace std;
const int N = 1e5 + 10;
const int INF = 1e18;
const int LOGN = 20;
int arr[N];
// pair<int, int> segment_tree[4 * N];
int up[N][LOGN];
int par[N];
// void build(int id, int l, int r)
// {
//     if (l == r)
//     {
//         segment_tree[id] = {arr[l - 1], l - 1};
//         return;
//     }
//     int mid = (l + r) / 2;
//     build(2 * id, l, mid);
//     build(2 * id + 1, mid + 1, r);
//     segment_tree[id] = min(segment_tree[2 * id], segment_tree[2 * id + 1]);
//     return;
// }
// pair<int, int> range(int id, int l, int r, int L, int R)
// {
//     if (R < l || L > r)
//     {
//         return {INF, INF};
//     }
//     if (L <= l && r <= R)
//     {
//         return segment_tree[id];
//     }
//     int mid = (l + r) / 2;
//     pair<int, int> x = range(2 * id, l, mid, L, R);
//     pair<int, int> y = range(2 * id + 1, mid + 1, r, L, R);
//     return min(x, y);
// }
struct Seg
{
    int siz;
    vector<pair<int, int>> v;

    void init(int n)
    {
        siz = 1;
        while (siz < n)
            siz *= 2;
        v.assign(siz * 2, make_pair(INF, -1));
    }

    pair<int, int> merge(pair<int, int> x, pair<int, int> y)
    {
        pair<int, int> res;
        res.first = min(x.first, y.first);
        if (x.first == y.first)
            res.second = min(x.second, y.second);
        else if (res.first == x.first)
            res.second = x.second;
        else
            res.second = y.second;
        return res;
    }

    void set(int i, pair<int, int> p, int x, int lx, int rx)
    {
        if (rx - lx == 1)
        {
            v[x] = merge(p, v[x]);
            return;
        }
        int m = (lx + rx) / 2;
        if (i < m)
            set(i, p, 2 * x + 1, lx, m);
        else
            set(i, p, 2 * x + 2, m, rx);
        v[x] = merge(v[2 * x + 1], v[2 * x + 2]);
    }

    void set(int i, pair<int, int> p)
    {
        set(i, p, 0, 0, siz);
    }

    pair<int, int> range_mx(int l, int r, int x, int lx, int rx)
    {
        if (l >= rx || lx >= r)
            return make_pair(INF, -1);
        if (lx >= l && rx <= r)
            return v[x];
        int m = (lx + rx) / 2;
        return merge(range_mx(l, r, 2 * x + 1, lx, m), range_mx(l, r, 2 * x + 2, m, rx));
    }

    pair<int, int> range_mx(int l, int r)
    {
        return range_mx(l, r, 0, 0, siz);
    }
};
void solve()
{
    int n, q;
    cin >> n >> q;
    vector<pair<int, int>> v1;
    vector<pair<int, pair<int, int>>> v2;
    for (int i = 0; i < n; ++i)
    {
        int l, r;
        cin >> l >> r;
        v1.push_back({l, r});
        v2.push_back({r, {l, i}});
    }
    int brr[n];
    sort(v2.begin(), v2.end());
    for (int i = 0; i < n; ++i)
    {
        arr[i] = v2[i].second.first;
        brr[v2[i].second.second] = i;
    }
    // build(1, 1, n);
    Seg st;
    st.init(n + 1);
    for (int i = n - 1; i >= 0; i--)
    {
        st.set(i, make_pair(v2[i].second.first, i));
    }

    for (int i = 0; i < n; ++i)
    {
        pair<int, pair<int, int>> p = {v2[i].second.first, {-1, -1}};
        int it = lower_bound(v2.begin(), v2.end(), p) - v2.begin();
        // cout << v2[i].first << ' ' << it << endl;
        if (it == i)
        {
            up[i][0] = par[i] = i;
        }
        else
        {
            // auto idx = range(1, 1, n, it + 1, i + 1);
            up[i][0] = par[i] = (st.range_mx(it, i)).second;
        }
    }
    for (int j = 1; j < LOGN; ++j)
    {
        for (int i = 0; i < n; ++i)
        {
            if (j == 1)
                up[i][j] = up[par[i]][j - 1];
            else
                up[i][j] = up[up[i][j - 1]][j - 1];
            // up[j][i] = up[up[j][i - 1]][i - 1];
        }
    }
    while (q--)
    {
        int s, e;
        cin >> s >> e;
        if (s == e)
        {
            cout << 0 << endl;
            continue;
        }
        s--, e--;
        s = brr[s], e = brr[e];
        int sl = v2[s].second.first, sr = v2[s].first;
        int el = v2[e].second.first, er = v2[e].first;
        if (s > e)
        {
            if (sl >= el && sr <= er)
            {
                cout << 1 << endl;
                continue;
            }
            else
            {
                cout << "impossible" << endl;
                continue;
            }
        }
        int curr = e;
        int ans = 0;
        for (int i = LOGN - 1; i >= 0; --i)
        {
            if (v2[up[curr][i]].first > sr)
            {
                ans += (1 << i);
                curr = up[curr][i];
            }
        }
        // if (v2[up[curr][0]].first > sr)
        // {
        //     ans++;
        //     curr = up[curr][0];
        // }
        ans++;
        curr = up[curr][0];
        if (v2[curr].first > sr)
        {
            cout << "impossible" << endl;
            continue;
        }
        else
        {
            cout << ans << endl;
        }
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    // freopen("prime_subtractorization_input.txt", "r", stdin);
    // freopen("out.txt", "w", stdout);
    int t = 1;
    // cin >> t;
    for (int tt = 1; tt <= t; ++tt)
    {
        // cout << "Case #" << tt << ": ";
        solve();
    }

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 78 ms 30280 KB Output is correct
3 Correct 77 ms 30272 KB Output is correct
4 Correct 84 ms 30276 KB Output is correct
5 Correct 85 ms 30268 KB Output is correct
6 Correct 88 ms 30292 KB Output is correct
7 Correct 81 ms 30308 KB Output is correct
8 Correct 67 ms 30792 KB Output is correct
9 Correct 69 ms 30648 KB Output is correct
10 Correct 95 ms 30524 KB Output is correct
11 Correct 85 ms 30528 KB Output is correct
12 Correct 63 ms 30056 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 688 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Incorrect 1 ms 556 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 688 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Incorrect 1 ms 556 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 688 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Incorrect 1 ms 556 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 75 ms 30188 KB Output is correct
2 Correct 81 ms 30160 KB Output is correct
3 Correct 89 ms 30280 KB Output is correct
4 Correct 74 ms 30788 KB Output is correct
5 Correct 96 ms 30532 KB Output is correct
6 Correct 95 ms 30208 KB Output is correct
7 Correct 107 ms 30340 KB Output is correct
8 Correct 86 ms 30532 KB Output is correct
9 Correct 50 ms 28484 KB Output is correct
10 Correct 76 ms 30016 KB Output is correct
11 Correct 73 ms 29756 KB Output is correct
12 Correct 77 ms 30024 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 78 ms 30280 KB Output is correct
3 Correct 77 ms 30272 KB Output is correct
4 Correct 84 ms 30276 KB Output is correct
5 Correct 85 ms 30268 KB Output is correct
6 Correct 88 ms 30292 KB Output is correct
7 Correct 81 ms 30308 KB Output is correct
8 Correct 67 ms 30792 KB Output is correct
9 Correct 69 ms 30648 KB Output is correct
10 Correct 95 ms 30524 KB Output is correct
11 Correct 85 ms 30528 KB Output is correct
12 Correct 63 ms 30056 KB Output is correct
13 Correct 1 ms 344 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 1 ms 688 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Incorrect 1 ms 556 KB Output isn't correct
19 Halted 0 ms 0 KB -