#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define pb emplace_back
#define lb(v,k) (lower_bound(all(v),(k))-v.begin())
#define ub(v,k) (upper_bound(all(v),(k))-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define all(a) a.begin(),a.end()
#define rsort(a) {sort(all(a));reverse(all(a));}
#define dupli(a) {sort(all(a));a.erase(unique(all(a)),a.end());}
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void outset(T s){auto itr=s.begin();while(itr!=s.end()){if(itr!=s.begin())cout<<' ';cout<<*itr;itr++;}cout<<'\n';}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}
struct UnionFind {
vector< int > data;
UnionFind() = default;
explicit UnionFind(size_t sz) : data(sz, -1) {}
bool unite(int x, int y) {
x = find(x), y = find(y);
if(x == y) return false;
if(data[x] > data[y]) swap(x, y);
data[x] += data[y];
data[y] = x;
return true;
}
int find(int k) {
if(data[k] < 0) return (k);
return data[k] = find(data[k]);
}
int size(int k) {
return -data[find(k)];
}
bool same(int x, int y) {
return find(x) == find(y);
}
vector< vector< int > > groups() {
int n = (int) data.size();
vector< vector< int > > ret(n);
for(int i = 0; i < n; i++) {
ret[find(i)].emplace_back(i);
}
ret.erase(remove_if(begin(ret), end(ret), [&](const vector< int > &v) {
return v.empty();
}));
return ret;
}
};
struct IncrementalBridgeConnectivity {
private:
UnionFind cc, bcc;
vector< int > bbf;
size_t bridge;
int size() {
return bbf.size();
}
int par(int x) {
return bbf[x] == size() ? size() : bcc.find(bbf[x]);
}
int lca(int x, int y) {
unordered_set< int > used;
for(;;) {
if(x != size()) {
if(!used.insert(x).second) return x;
x = par(x);
}
swap(x, y);
}
}
void compress(int x, int y) {
while(bcc.find(x) != bcc.find(y)) {
int nxt = par(x);
bbf[x] = bbf[y];
bcc.unite(x, y);
x = nxt;
--bridge;
}
}
void link(int x, int y) {
int v = x, pre = y;
while(v != size()) {
int nxt = par(v);
bbf[v] = pre;
pre = v;
v = nxt;
}
}
public:
IncrementalBridgeConnectivity() = default;
explicit IncrementalBridgeConnectivity(int sz) : cc(sz), bcc(sz), bbf(sz, sz), bridge(0) {}
int find(int k) {
return bcc.find(k);
}
size_t bridge_size() const {
return bridge;
}
bool add_edge(int x, int y) {
x = bcc.find(x);
y = bcc.find(y);
if(cc.find(x) == cc.find(y)) {
int w = lca(x, y);
compress(x, w);
compress(y, w);
return false;
} else {
if(cc.size(x) > cc.size(y)) swap(x, y);
link(x, y);
cc.unite(x, y);
++bridge;
return true;
}
}
};
int main(){
cin.tie(0);ios::sync_with_stdio(false);
ll n,m;cin>>n>>m;
vp tmp;
IncrementalBridgeConnectivity br(n);
rep(i,m){
ll a,b;cin>>a>>b;a--;b--;
if(br.add_edge(a,b))tmp.pb(a,b);
}
for(auto x:tmp){
if(br.find(x.fi)!=br.find(x.se))cout<<x.fi+1<<' '<<x.se+1<<endl;
}
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
588 KB |
Output is correct |
| 2 |
Correct |
5 ms |
588 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
190 ms |
5824 KB |
Output is correct |
| 2 |
Correct |
188 ms |
5700 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
309 ms |
10276 KB |
Output is correct |
| 2 |
Correct |
376 ms |
12176 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
488 ms |
17192 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
606 ms |
23084 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
944 ms |
35856 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1270 ms |
47008 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1603 ms |
58792 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
2013 ms |
65536 KB |
Memory limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
