oj.uz

답안 #697807

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
697807 2023-02-11T06:25:32 Z Duy_e Event Hopping (BOI22_events) C++14
25 / 100
 1500 ms 51056 KB 
#include <bits/stdc++.h>
#define ll long long
#define pii pair <ll, ll>
#define st first
#define nd second
#define rep(i, n, m) for (ll i = (n); i <= (m); i ++)
#define rrep(i, n, m) for (ll i = (n); i >= (m); i --)
using namespace std;

const long long INF = 1e18;
const long long N = 1e5 + 5;

ll n, q, s[N], e[N];
vector <int> cmp, out[2 * N], in[2 * N];
vector <int> d[N];

const ll Nmax = 5005;
int dist[Nmax][Nmax];
void bfs(int st, int *f) {
    rep(i, 1, n) f[i] = 1e9;
    f[st] = 0;
    queue <int> q;
    q.push(st);
    while (q.size()) {
        int u = q.front(); q.pop();
        for (int v: d[u]) if (f[v] > f[u] + 1) {
            f[v] = f[u] + 1;
            q.push(v);
        }
    }
}

namespace sub4 {

    pii a[N];
    ll pos[N], f[N];
    void solve() {
        rep(i, 1, n) a[i] = {e[i], i};
        sort(a + 1, a + 1 + n);
        rep(i, 1, n) pos[a[i].nd] = i;
        while (q --) {
            int u, v;
            cin >> u >> v;
            int i = pos[u];
            int j = pos[v];
            int l = j;

            if (i > j && a[j].st < a[i].st) {
                cout << "impossible\n";
                continue;
            }

            if (i > j) {
                cout << 1 << '\n';
                continue;
            }

            while (l + 1 <= n && a[l + 1].st == a[j].st) l ++;

            f[l + 1] = 1e9;
            //cout << i << ' ' << j << '\n';
            rrep(k, l, i) {
                int id = a[k].nd;
                f[k] = min(f[k + 1], s[id]);
            }
            int ans = 0;
            while (i < j) {
                ans ++;
                int cur = a[i].st, pre = i;
                while (i < l && cur >= f[i + 1]) {
                    i ++;
                }
                if (i > j) {
                    int id = a[j].nd;
                    if (cur >= s[v] && cur <= e[v])
                        break;
                    ans ++;
                    break;
                }
                if (i == pre) break;

            }

            //cout << i << ' ' << j << '\n';

            if (i >= j)
                cout << ans << '\n';
            else
                cout << "impossible\n";
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> q;
    rep(i, 1, n)
        cin >> s[i] >> e[i];

    if (q <= 100) {
        sub4 :: solve();
        return 0;
    }

    rep(i, 1, n) rep(j, 1, n) if (i != j)
        if (s[j] <= e[i] && e[i] <= e[j])
            d[i].push_back(j);

    rep(i, 1, n) bfs(i, dist[i]);

    while (q --) {
        int u, v;
        cin >> u >> v;
        if (dist[u][v] >= (int)1e9)
            cout << "impossible\n";
        else
            cout << dist[u][v] << '\n';
    }

    return 0;
}

Compilation message

events.cpp: In function 'void sub4::solve()':
events.cpp:74:25: warning: unused variable 'id' [-Wunused-variable]
   74 |                     int id = a[j].nd;
      |                         ^~

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Execution timed out 1594 ms 13976 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12048 KB Output is correct
3 Correct 7 ms 12072 KB Output is correct
4 Correct 6 ms 12116 KB Output is correct
5 Correct 6 ms 12060 KB Output is correct
6 Correct 6 ms 12116 KB Output is correct
7 Correct 6 ms 12116 KB Output is correct
8 Correct 7 ms 12116 KB Output is correct
9 Correct 8 ms 12004 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12048 KB Output is correct
3 Correct 7 ms 12072 KB Output is correct
4 Correct 6 ms 12116 KB Output is correct
5 Correct 6 ms 12060 KB Output is correct
6 Correct 6 ms 12116 KB Output is correct
7 Correct 6 ms 12116 KB Output is correct
8 Correct 7 ms 12116 KB Output is correct
9 Correct 8 ms 12004 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 7 ms 11988 KB Output is correct
12 Correct 7 ms 12116 KB Output is correct
13 Correct 7 ms 12116 KB Output is correct
14 Correct 6 ms 12048 KB Output is correct
15 Correct 6 ms 12116 KB Output is correct
16 Correct 7 ms 12116 KB Output is correct
17 Correct 6 ms 12116 KB Output is correct
18 Correct 6 ms 12084 KB Output is correct
19 Execution timed out 1599 ms 51056 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12048 KB Output is correct
3 Correct 7 ms 12072 KB Output is correct
4 Correct 6 ms 12116 KB Output is correct
5 Correct 6 ms 12060 KB Output is correct
6 Correct 6 ms 12116 KB Output is correct
7 Correct 6 ms 12116 KB Output is correct
8 Correct 7 ms 12116 KB Output is correct
9 Correct 8 ms 12004 KB Output is correct
10 Correct 6 ms 12088 KB Output is correct
11 Correct 6 ms 11988 KB Output is correct
12 Correct 7 ms 12132 KB Output is correct
13 Correct 6 ms 12132 KB Output is correct
14 Correct 7 ms 12096 KB Output is correct
15 Correct 7 ms 12076 KB Output is correct
16 Correct 7 ms 12132 KB Output is correct
17 Correct 7 ms 12116 KB Output is correct
18 Correct 6 ms 12116 KB Output is correct
19 Correct 85 ms 16780 KB Output is correct
20 Correct 37 ms 16728 KB Output is correct
21 Correct 42 ms 16728 KB Output is correct
22 Correct 44 ms 16632 KB Output is correct
23 Correct 40 ms 16740 KB Output is correct
24 Correct 70 ms 16748 KB Output is correct
25 Correct 61 ms 16596 KB Output is correct

Subtask #5
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1581 ms 13764 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Execution timed out 1594 ms 13976 KB Time limit exceeded
3 Halted 0 ms 0 KB -