結果
問題 | No.1553 Lovely City |
ユーザー |
|
提出日時 | 2021-06-18 22:11:31 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 606 ms / 2,000 ms |
コード長 | 3,167 bytes |
コンパイル時間 | 3,345 ms |
コンパイル使用メモリ | 215,008 KB |
最終ジャッジ日時 | 2025-01-22 09:22:38 |
ジャッジサーバーID (参考情報) |
judge2 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 26 |
ソースコード
#include<bits/stdc++.h>using namespace std;#define rep(i,n) for(ll i=0;i<n;i++)#define repl(i,l,r) for(ll i=(l);i<(r);i++)#define per(i,n) for(ll i=(n)-1;i>=0;i--)#define perl(i,r,l) for(ll i=r-1;i>=l;i--)#define fi first#define se second#define pb push_back#define ins insert#define pqueue(x) priority_queue<x,vector<x>,greater<x>>#define all(x) (x).begin(),(x).end()#define CST(x) cout<<fixed<<setprecision(x)#define vtpl(x,y,z) vector<tuple<x,y,z>>#define rev(x) reverse(x);using ll=long long;using vl=vector<ll>;using vvl=vector<vector<ll>>;using pl=pair<ll,ll>;using vpl=vector<pl>;using vvpl=vector<vpl>;const ll MOD=1000000007;const ll MOD9=998244353;const int inf=1e9+10;const ll INF=4e18;const ll dy[9]={0,1,-1,0,1,1,-1,-1,0};const ll dx[9]={1,0,0,-1,1,-1,1,-1,0};template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}struct UnionFind {vector<int> par;vector<int> edge;UnionFind(int n) : par(n, -1),edge(n, 0) {}int root(int x) {if (par[x] < 0) return x;else return par[x] = root(par[x]);}bool same(int x, int y) {return root(x) == root(y);}bool merge(int x, int y) {x = root(x); y = root(y);if (x == y) {edge[x]++;return false;}if (par[x] > par[y]) swap(x, y);par[x] += par[y];par[y] = x;edge[x] += edge[y]+1;return true;}int size(int x) {return -par[root(x)];}};vl topsort(vvl &g){ll n=g.size();vl ans,ind(n);rep(i,n)for(auto e:g[i])ind[e]++;queue<ll> que;rep(i,n)if(!ind[i])que.push(i);while(!que.empty()){ll v=que.front();que.pop();ans.pb(v);for(auto nv:g[v]){ind[nv]--;if(!ind[nv])que.push(nv);}}return ans;}int main(){ll n,m;cin >> n >>m;vpl edge(m);UnionFind uf(n);rep(i,m){ll a,b;cin >> a >> b;a--;b--;edge[i]={a,b};uf.merge(a,b);}vector<vpl> es(n);rep(i,m){es[uf.root(edge[i].fi)].push_back(edge[i]);}vpl ans;rep(i,n){if(es[i].empty())continue;vl pls;for(auto p:es[i]){pls.push_back(p.first);pls.push_back(p.se);}sort(all(pls));pls.erase(unique(all(pls)),pls.end());ll z=pls.size();vvl g(z);for(auto p:es[i]){ll a=lower_bound(all(pls),p.first)-pls.begin();ll b=lower_bound(all(pls),p.second)-pls.begin();g[a].push_back(b);}auto tps=topsort(g);if(tps.size()!=z){rep(j,z)ans.push_back({pls[j],pls[(j+1)%z]});}else{rep(j,z-1){ans.push_back({pls[tps[j]],pls[tps[j+1]]});}}}cout << ans.size() <<endl;for(auto p:ans)cout << p.fi+1 <<" " << p.se+1 <<endl;}