#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define FastIO cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define FileIO freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#define F first
#define S second
#define max_heap(T) priority_queue<T>
#define min_heap(T) priority_queue<T, vector<T>, greater<T>>
#define fr(i,a,b) for(int i=a;i<b;i++)
#define frr(i,a,b) for(int i=a;i>b;i--)
#define frin(i,A) for(auto &i : A)
#define frp(a,b,A) for(auto [a, b] : A)
#define SZ(x) (int)x.size()
#define all(A) A.begin(), A.end()
#define mins(a,b) a = min(a,b)
#define maxs(a,b) a = max(a,b)
#define pb push_back
#define kill(x) cout << x << '\n', exit(0)
#define md(a) (a%MOD+MOD)%MOD
const ll INF = 2e9;
const ll MOD = 1e9 + 7;
const int MAXN = 1e5 + 5;
const int LOG = 30;
int n, m, par[MAXN][2], hi[MAXN];
vector<int> g[MAXN];
void DSU() {
fr(i, 1, n+1)
par[i][0] = par[i][1] = i;
}
int Find(int v, int x) { return v == par[v][x] ? v : par[v][x] = Find(par[v][x], x); }
void Union(int u, int v) {
if(Find(u, 0) != Find(v, 0)) {
par[Find(u, 0)][0] = Find(v, 0);
g[u].pb(v);
g[v].pb(u);
return;
}
if(Find(u, 1) != Find(v, 1)) {
par[Find(u, 1)][1] = Find(v, 1);
g[u].pb(v);
g[v].pb(u);
return;
}
}
int dfs(int v, int p) {
hi[v] = hi[p]+1;
int res = 0;
frin(u, g[v])
if(u == p)
continue;
else if(!hi[u])
res += dfs(u, v);
else if(hi[u] < hi[v])
res++;
else
res--;
if(v != p && res == 0)
cout << v << ' ' << p << '\n';
return res;
}
void solve() {
cin >> n >> m;
DSU();
int u, v;
while(m--) {
cin >> u >> v;
Union(u, v);
}
fr(i, 1, n+1)
if(!hi[i])
dfs(i, i);
}
int32_t main() {
FastIO
int T = 1;
// cin >> T;
while(T--)
solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2648 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
3164 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
76 ms |
8596 KB |
Output is correct |
2 |
Incorrect |
65 ms |
8336 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
113 ms |
13140 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
227 ms |
20512 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
296 ms |
29716 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
408 ms |
41876 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
532 ms |
52976 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
673 ms |
63412 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
852 ms |
65536 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |