oj.uz

Submission #1109033

# Submission time Handle Problem Language Result Execution time Memory
1109033 2024-11-05T20:42:29 Z n3rm1n Event Hopping (BOI22_events) C++17
0 / 100
 3 ms 1104 KB 
#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
const int MAXN = 5e3 + 10;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
int n, q, s[MAXN], e[MAXN];
void read_events()
{
    cin >> n >> q;
    for (int i = 1; i <= n; ++ i)
        cin >> s[i] >> e[i];
}
vector < int > g[MAXN];

void make_edges()
{
    for (int i = 1; i <= n; ++ i)
    {
        for (int j = 1; j <= n; ++ j)
        {
            if(i == j)continue;
            if(s[j] <= e[i] && e[i] <= e[j])
                g[i].push_back(j);
        }
    }
}
vector < pair < int, int > > que[MAXN];
int ans[MAXN];
int start, dist[MAXN], used[MAXN];
void bfs()
{
    for (int i = 1; i <= n; ++ i)
    {
        dist[i] = 1e9;
    }
    queue < int > q;
    q.push(start);
    used[start] = 1;
    dist[start] = 0;
    while(!q.empty())
    {
        int beg = q.front();
        q.pop();
        for (auto nb: g[beg])
        {
            if(used[nb])continue;
            dist[nb] = dist[beg] + 1;
            used[nb] = 1;
            q.push(nb);
        }
    }
}
void sort_queries()
{
    for (int i = 1; i <= q; ++ i)
    {
        int from, to;
        cin >> from >> to;
        que[from].push_back(make_pair(to, i));
    }
}
int main()
{
    speed();

    read_events();
    make_edges();
    sort_queries();
    for (int i = 1; i <= n; ++ i)
    {
        if(!que[i].size())continue;
        start = i;
        bfs();
        for (auto &[v, qi]: que[i])
        {
            ans[qi] = dist[v];
        }
    }
    for (int i = 1; i <= q; ++ i)
    {
        assert(ans[i] <= 1e9);
        assert(ans[i] >= 0);
        if(ans[i] == 1e9)cout << "impossible" << endl;
        else cout << ans[i] << endl;
    }
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 592 KB Output is correct
2 Runtime error 3 ms 1104 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 592 KB Output is correct
2 Correct 1 ms 592 KB Output is correct
3 Incorrect 3 ms 592 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 592 KB Output is correct
2 Correct 1 ms 592 KB Output is correct
3 Incorrect 3 ms 592 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 592 KB Output is correct
2 Correct 1 ms 592 KB Output is correct
3 Incorrect 3 ms 592 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Runtime error 3 ms 1104 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 592 KB Output is correct
2 Runtime error 3 ms 1104 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -