Submission #881927

#	Time	Username	Problem	Language	Result	Execution time	Memory
881927		12345678	Synchronization (JOI13_synchronization)	C++17	30 / 100	58 ms	23128 KiB

synchronization

#include <bits/stdc++.h>

using namespace std;

const int nx=1e5+5;
int n, m, q, u, v, on[nx], x, dp[nx];
vector<pair<int, int>> d[nx], t[2*nx];

void dfs(int u, int p, int l)
{
    dp[u]=1;
    for (auto [v, idx]:d[u])
    {
        if (v==p||t[idx].empty()) continue;
        auto itr=lower_bound(t[idx].begin(), t[idx].end(), make_pair(l, INT_MAX));
        if (itr==t[idx].begin()) continue;
        dfs(v, u, min(prev(itr)->second, l));
        dp[u]+=dp[v];
    }
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m>>q;
    for (int i=1; i<n; i++) cin>>u>>v, d[u].push_back({v, i}), d[v].push_back({u, i});
    for (int i=1; i<=m; i++)
    {
        cin>>x;
        if (on[x]) t[x].push_back({on[x], i}), on[x]=0;
        else on[x]=i;
    }
    for (int i=1; i<n; i++) if (on[i]) t[i].push_back({on[i], m});
    cin>>x;
    dfs(x, x, m);
    cout<<dp[x];
}

/*
5 6 3
1 2
1 3
2 4
2 5
1
2
1
4
4
3
4
*/

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40