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Submission #1026476

# Submission time Handle Problem Language Result Execution time Memory
1026476 2024-07-18T06:40:38 Z gyg Event Hopping (BOI22_events) C++17
0 / 100
 1500 ms 14576 KB 
#include <bits/stdc++.h>    
using namespace std;
using pii = pair<int, int>;
const int MAX_N = 1e5 + 5, INF = 1e9;

int n, q;
array<int, MAX_N> l, r;

vector<pii> ord; // {r, i}
int n_ccs;
unordered_map<int, int> cc;
void precomp() {
    for (int i = 1; i <= n; i++) ord.push_back({r[i], i});
    sort(ord.rbegin(), ord.rend());

    set<int> coords;
    for (int i = 1; i <= n; i++) coords.insert(l[i]), coords.insert(r[i]);
    while (coords.size()) {
        n_ccs++, cc[*coords.begin()] = n_ccs;
        coords.erase(coords.begin());
    }
}

array<int, 8 * MAX_N> st;
void update(int l, int r, int x, int u = 1, int lo = 1, int hi = n_ccs) {
    if (r < lo || hi < l) return;
    if (l <= lo && hi <= r) { st[u] = min(st[u], x); return; }
    int mid = (lo + hi) / 2;
    update(l, r, x, 2 * u, lo, mid), update(l, r, x, 2 * u + 1, mid + 1, hi);
}
int query(int i, int u = 1, int lo = 1, int hi = n_ccs) {
    if (i < lo || hi < i) return INF;
    if (lo == hi) return st[u];
    int mid = (lo + hi) / 2;
    return min({st[u], query(i, 2 * u, lo, mid), query(i, 2 * u + 1, mid + 1, hi)});
}

array<int, MAX_N> dp;
void comp(int f) {
    fill(st.begin(), st.end(), INF);

    for (pii x : ord) {
        int i = x.second;
        if (i == f) dp[i] = 0;
        else dp[i] = query(cc[r[i]]) + 1;
        update(cc[l[i]], cc[r[i]], dp[i]);
    }
} 

int main() {
    // freopen("event.in", "r", stdin);
    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> l[i] >> r[i];
    
    precomp();

    for (int i = 1; i <= q; i++) {
        int s, f; cin >> s >> f;
        comp(f);
        cout << ((dp[s] >= INF) ? "impossible" : to_string(dp[s])) << '\n';
    }
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4444 KB Output is correct
2 Execution timed out 1589 ms 14576 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4444 KB Output is correct
2 Correct 3 ms 4444 KB Output is correct
3 Correct 69 ms 4444 KB Output is correct
4 Correct 70 ms 4444 KB Output is correct
5 Correct 68 ms 4444 KB Output is correct
6 Incorrect 79 ms 4700 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 4444 KB Output is correct
2 Correct 3 ms 4444 KB Output is correct
3 Correct 69 ms 4444 KB Output is correct
4 Correct 70 ms 4444 KB Output is correct
5 Correct 68 ms 4444 KB Output is correct
6 Incorrect 79 ms 4700 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 4444 KB Output is correct
2 Correct 3 ms 4444 KB Output is correct
3 Correct 69 ms 4444 KB Output is correct
4 Correct 70 ms 4444 KB Output is correct
5 Correct 68 ms 4444 KB Output is correct
6 Incorrect 79 ms 4700 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1559 ms 14388 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4444 KB Output is correct
2 Execution timed out 1589 ms 14576 KB Time limit exceeded
3 Halted 0 ms 0 KB -