#include <bits/stdc++.h>
using namespace std;
const int nax = 5e5 + 5;
vector<pair<int, int>> edges[nax];
int deg[nax], where[nax];
bool used[nax];
void solve() {
int n, m;
cin >> n >> m;
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
++deg[u], ++deg[v];
edges[u].push_back({v, i});
edges[v].push_back({u, i});
}
vector<int> st = {1}, ans;
int at = 1;
while (!st.empty()) {
if (deg[at]) {
st.push_back(at);
while (used[edges[at].back().second]) {
edges[at].pop_back();
}
--deg[at];
used[edges[at].back().second] = 1;
at = edges[at].back().first;
--deg[at];
} else {
ans.push_back(at);
at = st.back();
st.pop_back();
}
}
vector<pair<int, int>> stt;
for (int i = 0; i < nax; ++i) {
where[i] = -1;
}
for (int i = 0; i < ans.size(); ++i) {
stt.push_back({ans[i], i});
if (where[ans[i]] != -1) {
int x = where[ans[i]];
while (stt.back().second > x) {
where[stt.back().first] = -1;
cout << stt.back().first << ' ';
stt.pop_back();
}
where[ans[i]] = stt.back().second;
cout << ans[i] << '\n';
} else {
where[ans[i]] = i;
}
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
solve();
}
Compilation message
postmen.cpp: In function 'void solve()':
postmen.cpp:43:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
43 | for (int i = 0; i < ans.size(); ++i) {
| ~~^~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
14036 KB |
Same junction appears twice in a route |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
13996 KB |
Same junction appears twice in a route |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
14036 KB |
Same junction appears twice in a route |
2 |
Halted |
0 ms |
0 KB |
- |