Submission #1161749

#	Time	Username	Problem	Language	Result	Execution time	Memory
1161749		12345678	Senior Postmen (BOI14_postmen)	C++20	100 / 100	429 ms	103700 KiB

postmen

#include <bits/stdc++.h>

using namespace std;

const int nx=5e5+5;

int n, m, u, v, used[nx], cy[nx], t;
vector<pair<int, int>> d[nx];
vector<int> res[nx];

void dfs(int u, int pidx, int p)
{
    //cout<<"debug "<<u<<' '<<p<<'\n';
    for (auto [v, idx]:d[u])
    {
        if (used[idx]||v==p) continue;
        cy[u]=1;
        if (cy[v]==1)
        {
            //cout<<"find cycle "<<v<<'\n';
            cy[v]=2;
            used[idx]=1;
            res[t].push_back(v);
        }
        else
        {
            dfs(v, idx, u);
        }
        if (cy[u]==1)
        {
            //cout<<"go back "<<u<<'\n';
            cy[u]=0;
            res[t].push_back(u);
            used[pidx]=1;
            return;
        }
        if (cy[u]==2) t++;
    }
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m;
    for (int i=1; i<=m; i++) cin>>u>>v, d[u].push_back({v, i}), d[v].push_back({u, i});
    for (int i=1; i<=n; i++) dfs(i, -1, -1);
    for (int i=0; i<t; i++)
    {
        for (auto x:res[i]) cout<<x<<' ';
        cout<<'\n';
    }
}

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 45 / 45