oj.uz

Submission #750600

# Submission time Handle Problem Language Result Execution time Memory
750600 2023-05-29T21:11:17 Z stevancv Event Hopping (BOI22_events) C++14
30 / 100
 182 ms 34248 KB 
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 1e5 + 2;
const int inf = 1e9;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, q;
    cin >> n >> q;
    vector<int> l(n), r(n);
    for (int i = 0; i < n; i++) {
        cin >> l[i] >> r[i];
    }
    vector<int> order(n);
    iota(order.begin(), order.end(), 0);
    sort(order.begin(), order.end(), [&] (int i, int j) {
        if (r[i] != r[j]) return r[i] < r[j];
        return l[i] < l[j];
    });
    vector<int> gdesibreti(n);
    for (int i = 0; i < n; i++) gdesibreti[order[i]] = i;
    vector<int> tl(n), tr(n);
    for (int i = 0; i < n; i++) {
        tl[i] = l[order[i]];
        tr[i] = r[order[i]];
    }
    swap(l, tl); swap(r, tr);
    vector<vector<pair<int, int>>> rmq(n, vector<pair<int, int>>(17));
    for (int i = 0; i < n; i++) rmq[i][0] = {l[i], i};
    for (int j = 1; j < 17; j++) {
        for (int i = 0; i + (1 << j) <= n; i++) {
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
        }
    }
    vector<int> logs(n + 1);
    int z = 0;
    for (int i = 1; i <= n; i++) {
        if (i == (1 << (z + 1))) z += 1;
        logs[i] = z;
    }
    auto Query = [&] (int l, int r) {
        int o = logs[r - l + 1];
        return min(rmq[l][o], rmq[r - (1 << o) + 1][o]);
    };
    vector<int> dokle(n, -1);
    for (int i = 0; i < n; i++) {
        int lo = 0, hi = i - 1, idx = i;
        while (lo <= hi) {
            int mid = lo + hi >> 1;
            if (l[i] <= r[mid]) {
                hi = mid - 1;
                idx = mid;
            }
            else lo = mid + 1;
        }
        dokle[i] = idx;
    }
    vector<vector<int>> lift(n, vector<int>(17));
    for (int i = 0; i < n; i++) lift[i][0] = dokle[i];
    for (int j = 1; j < 17; j++) {
        for (int i = 0; i < n; i++) {
            lift[i][j] = lift[Query(lift[i][j - 1], i).second][j - 1];
        }
    }
    while (q--) {
        int a, b;
        cin >> a >> b;
        a -= 1; b -= 1;
        a = gdesibreti[a]; b = gdesibreti[b];
        if (a == b) {
            cout << 0 << en;
            continue;
        }
        if (l[b] <= r[a] && r[a] <= r[b]) {
            cout << 1 << en;
            continue;
        }
        if (a > b) {
            cout << "impossible" << en;
            continue;
        }
        int ans = 0;
        for (int i = 16; i >= 0; i--) {
            if (a < lift[b][i]) {
                ans += (1 << i);
                b = lift[b][i];
            }
        }
        if (a < lift[b][0]) cout << "impossible" << en;
        else cout << ans + 1 << en;
    }
    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:56:26: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   56 |             int mid = lo + hi >> 1;
      |                       ~~~^~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 152 ms 33688 KB Output is correct
3 Correct 129 ms 33764 KB Output is correct
4 Correct 135 ms 33784 KB Output is correct
5 Correct 130 ms 33848 KB Output is correct
6 Correct 132 ms 33812 KB Output is correct
7 Correct 182 ms 33948 KB Output is correct
8 Correct 133 ms 34240 KB Output is correct
9 Correct 150 ms 34248 KB Output is correct
10 Correct 168 ms 34128 KB Output is correct
11 Correct 163 ms 34116 KB Output is correct
12 Correct 128 ms 33464 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 608 KB Output is correct
4 Correct 1 ms 596 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Incorrect 1 ms 596 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 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 608 KB Output is correct
4 Correct 1 ms 596 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Incorrect 1 ms 596 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 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 608 KB Output is correct
4 Correct 1 ms 596 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Incorrect 1 ms 596 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 123 ms 33816 KB Output is correct
2 Correct 151 ms 33748 KB Output is correct
3 Correct 135 ms 33700 KB Output is correct
4 Correct 129 ms 34156 KB Output is correct
5 Correct 161 ms 34016 KB Output is correct
6 Correct 166 ms 33856 KB Output is correct
7 Correct 172 ms 33808 KB Output is correct
8 Correct 128 ms 34084 KB Output is correct
9 Correct 88 ms 31944 KB Output is correct
10 Correct 118 ms 33472 KB Output is correct
11 Correct 111 ms 33256 KB Output is correct
12 Correct 122 ms 33508 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 152 ms 33688 KB Output is correct
3 Correct 129 ms 33764 KB Output is correct
4 Correct 135 ms 33784 KB Output is correct
5 Correct 130 ms 33848 KB Output is correct
6 Correct 132 ms 33812 KB Output is correct
7 Correct 182 ms 33948 KB Output is correct
8 Correct 133 ms 34240 KB Output is correct
9 Correct 150 ms 34248 KB Output is correct
10 Correct 168 ms 34128 KB Output is correct
11 Correct 163 ms 34116 KB Output is correct
12 Correct 128 ms 33464 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 608 KB Output is correct
16 Correct 1 ms 596 KB Output is correct
17 Correct 1 ms 596 KB Output is correct
18 Incorrect 1 ms 596 KB Output isn't correct
19 Halted 0 ms 0 KB -