Submission #1038202

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038202		vjudge1	Senior Postmen (BOI14_postmen)	C++17	100 / 100	294 ms	125884 KiB

postmen

#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pld pair<ld, ld>
#define pb push_back
#define fi first
#define se second
#define debug(x) cerr << #x << " => " << x << endl
#define all(x) x.begin(),x.end()

int n,m;
vector<int> adj[500010];
bool vis[500010];
priority_queue<int> pq[500010];
vector<pii> p;

void solve()
{
	stack<pii> st;
	for(auto i : p) 
	{
		st.push(i);
		vis[i.fi]=1;
		if(vis[i.se])
		{
			while(st.top().fi!=i.se)
			{
				cout<<st.top().fi<<' ';
				vis[st.top().fi]=0;
				st.pop();
			}
			cout<<i.se<<'\n';
			vis[i.se]=0;
			st.pop();
		}
	}
	exit(0);
}

void dfs(int u)
{
	if(p.size()==m) solve();
	// debug(u);
	// debug(adj[u].size());
	while(!pq[u].empty() && pq[u].top()==adj[u].back())
	{
		pq[u].pop();
		adj[u].pop_back();
	}
	while(!adj[u].empty())
	{
		int v=adj[u].back();
		pq[u].push(v);
		pq[v].push(u);
		p.pb({u,v});
		dfs(v);
	}
}

int main()
{
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
	cin>>n>>m;
	for(int i=0;i<m;i++)
	{
		int u,v;cin>>u>>v;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	for(int i=1;i<=n;i++) sort(all(adj[i]));
	for(int i=1;i<=n;i++) dfs(i);
	// for(auto i : p) cerr<<i.fi<<" "<<i.se<<'\n'; 
	return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'void dfs(int)':
postmen.cpp:46:13: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |  if(p.size()==m) solve();
      |     ~~~~~~~~^~~

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