#include <bits/stdc++.h>
using namespace std;
#define REP(i, j, k) for (int i = j; i < k; i++)
#define RREP(i, j, k) for (int i = j; i >= k; i--)
template<class T>
inline bool mxto(T &a, T b) {return a < b ? a = b, 1 : 0;}
template<class T>
inline bool mnto(T &a, T b) {return a > b ? a = b, 1 : 0;}
typedef long long ll;
#define FI first
#define SE second
#define MP make_pair
typedef pair<int, int> ii;
#define pb push_back
#define ALL(x) x.begin(), x.end()
typedef vector<int> vi;
typedef vector<ii> vii;
#ifndef DEBUG
#define cerr if (0) cerr
#endif
#define INF 1000000005
#define LINF 1000000000000000005ll
#define MAXN 1005
#define MAXR 200005
int n, r;
vi adj[MAXN], nadj[MAXR];
int grid[MAXN][MAXN];
ii eg[MAXR];
int vis[MAXR];
int p[MAXR];
bool done;
void dfs(int u) {
vis[u] = 2;
for (int v : nadj[u]) {
if (p[u] == v) continue;
if (!vis[v]) {
p[v] = u;
dfs(v);
if (done) {
return;
}
} else if (vis[v] == 2) {
vi tans;
tans.pb(v);
while (u != v) {
assert(u != -1);
tans.pb(u);
u = p[u];
}
vi ans;
ans.pb(eg[tans[0]].SE);
ans.pb(eg[tans[0]].FI);
REP (i, 1, tans.size() - 1) {
auto [a, b] = eg[tans[i]];
ans.pb(a);
}
assert(eg[tans.back()] == MP(ans[0], ans.back()));
for (int i : ans) {
cout << i << ' ';
}
cout << '\n';
done = 1;
return;
}
}
vis[u] = 1;
}
int main() {
#ifdef DEBUG
ios::sync_with_stdio(0), cin.tie(0);
#endif
cin >> n >> r;
memset(grid, -1, sizeof grid);
REP (i, 0, r) {
int a, b; cin >> a >> b;
adj[a].pb(b);
adj[b].pb(a);
grid[a][b] = i;
grid[b][a] = i + r;
eg[i] = MP(a, b);
eg[i + r] = MP(b, a);
}
REP (i, 0, 2 * r) {
auto [a, b] = eg[i];
REP (j, 1, n + 1) {
if (j == a) continue;
if (grid[b][j] == -1) continue;
if (grid[a][j] != -1) continue;
nadj[i].pb(grid[b][j]);
cerr << i << " --- " << grid[b][j] << '\n';
}
}
REP (i, 0, 2 * r) {
if (vis[i]) continue;
p[i] = -1;
dfs(i);
if (done) {
return 0;
}
}
cout << "no\n";
}
/*
8 12
1 2
2 3
1 3
2 4
4 5
2 5
5 6
5 7
6 7
3 6
6 8
8 3
*/
Compilation message
indcyc.cpp: In function 'void dfs(int)':
indcyc.cpp:4:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
4 | #define REP(i, j, k) for (int i = j; i < k; i++)
......
60 | REP (i, 1, tans.size() - 1) {
| ~~~~~~~~~~~~~~~~~~~~~
indcyc.cpp:60:13: note: in expansion of macro 'REP'
60 | REP (i, 1, tans.size() - 1) {
| ^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
8908 KB |
Output is correct |
2 |
Correct |
5 ms |
8908 KB |
Output is correct |
3 |
Correct |
4 ms |
8908 KB |
Output is correct |
4 |
Correct |
4 ms |
8892 KB |
Output is correct |
5 |
Correct |
5 ms |
8908 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
8908 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
8952 KB |
Output is correct |
2 |
Correct |
4 ms |
8908 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
5 ms |
8908 KB |
Wrong adjacency |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
9164 KB |
Output is correct |
2 |
Correct |
6 ms |
9292 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
11 ms |
9292 KB |
Output is correct |
2 |
Correct |
13 ms |
9296 KB |
Output is correct |
3 |
Correct |
20 ms |
11232 KB |
Output is correct |
4 |
Correct |
18 ms |
11216 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
12 ms |
10544 KB |
Output is correct |
2 |
Correct |
12 ms |
10572 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
246 ms |
25804 KB |
Output is correct |
2 |
Correct |
82 ms |
12544 KB |
Output is correct |
3 |
Correct |
254 ms |
25920 KB |
Output is correct |
4 |
Correct |
83 ms |
12684 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
111 ms |
54008 KB |
Output is correct |
2 |
Correct |
152 ms |
58144 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
136 ms |
11996 KB |
Output is correct |
2 |
Correct |
137 ms |
12888 KB |
Output is correct |
3 |
Correct |
357 ms |
93368 KB |
Output is correct |
4 |
Correct |
377 ms |
94020 KB |
Output is correct |