#include <bits/stdc++.h>
using namespace std;
int main() {
int n, r; cin >> n >> r;
vector<vector<pair<int, int>>> g(n);
vector<pair<int, int>> edges;
vector<vector<bool>> m(n, vector<bool>(n));
for (int i = 0; i < n; ++i)
m[i][i] = true;
for (int i = 0; i < r; ++i) {
int a, b; cin >> a >> b; --a; --b;
g[a].emplace_back(b, 2*i);
g[b].emplace_back(a, 2*i+1);
edges.emplace_back(a, b);
edges.emplace_back(b, a);
m[a][b] = true;
m[b][a] = true;
}
vector<vector<int>> h(2*r);
for (int e = 0; e < 2*r; ++e) {
auto [u, v] = edges[e];
for (auto [w, f] : g[v])
if (w != u && !m[u][w])
h[e].push_back(f);
}
vector<int> color(2*r);
vector<int> stack;
vector<int> answer;
auto dfs = [&](auto&& self, int v, int p) -> bool {
if (color[v] == 1) {
assert(count(stack.begin(), stack.end(), v)>=1);
answer.push_back(edges[v].first);
while (stack.back() != v) {
answer.push_back(edges[stack.back()].first);
stack.pop_back();
}
return true;
}
if (color[v] == 2)
return false;
color[v] = 1;
stack.push_back(v);
for (auto w : h[v])
if (w != p)
if (self(self, w, v))
return true;
stack.pop_back();
color[v] = 2;
return false;
};
for (int i = 0; i < 2*r; ++i) {
assert(stack.empty());
if (color[i]==0)
if (dfs(dfs, i, -1))
break;
}
if (answer.empty()) {
cout << "no\n";
} else {
for (int i = 0; i < (int)answer.size(); ++i)
cout << answer[i]+1 << ' ';
cout << '\n';
}
}
Compilation message
indcyc.cpp: In function 'int main()':
indcyc.cpp:23:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
23 | auto [u, v] = edges[e];
| ^
indcyc.cpp:24:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
24 | for (auto [w, f] : g[v])
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
600 KB |
Output is correct |
2 |
Correct |
2 ms |
604 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
860 KB |
Output is correct |
2 |
Correct |
2 ms |
860 KB |
Output is correct |
3 |
Correct |
6 ms |
3120 KB |
Output is correct |
4 |
Correct |
8 ms |
3084 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
2140 KB |
Output is correct |
2 |
Correct |
4 ms |
2140 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
72 ms |
20168 KB |
Output is correct |
2 |
Correct |
20 ms |
5584 KB |
Output is correct |
3 |
Correct |
69 ms |
20164 KB |
Output is correct |
4 |
Correct |
19 ms |
5588 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
51 ms |
46796 KB |
Output is correct |
2 |
Correct |
78 ms |
50884 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
120 ms |
10008 KB |
Output is correct |
2 |
Correct |
102 ms |
9916 KB |
Output is correct |
3 |
Correct |
130 ms |
89288 KB |
Output is correct |
4 |
Correct |
166 ms |
89284 KB |
Output is correct |