Submission #31480

#	Time	Username	Problem	Language	Result	Execution time	Memory
31480		cheater2k	Senior Postmen (BOI14_postmen)	C++14	55 / 100	524 ms	53332 KiB

postmen

#include <bits/stdc++.h>
using namespace std;

const int N = 500010;

int n, m;
vector < pair<int,int> > G[N];
vector <int> E;
bool del[N];
int pos[N];

void dfs(int u) {
	while(!G[u].empty()) {
		int id = G[u].back().first, v = G[u].back().second;
		if (del[id]) { G[u].pop_back(); continue; }
		else del[id] = 1, dfs(v);
	}
	E.push_back(u);
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n >> m;
	for (int i = 1; i <= m; ++i) {
		int u, v; cin >> u >> v;
		G[u].push_back(make_pair(i,v));
		G[v].push_back(make_pair(i,u));
	}

	dfs(1);
	//for (int u: E) cerr << u << ' '; cerr << endl;

	stack <int> s;

	for (int i = 0; i < (int)E.size(); ++i) {
		int u = E[i];
		if (!pos[u]) {
			pos[u] = i + 1;
			s.push(i);
			continue;
		} else {
			int stop = pos[u] - 1;
			while(!s.empty()) {
				int t = s.top();
				printf("%d ", E[t]);
				pos[E[t]] = 0;
				s.pop();
				if (t == stop) break;
			}
			printf("\n");
			s.push(i);
			pos[u] = i + 1;
		}
	}
}

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45