結果
問題 | No.1553 Lovely City |
ユーザー |
👑 ![]() |
提出日時 | 2021-06-18 21:50:47 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 277 ms / 2,000 ms |
コード長 | 8,612 bytes |
コンパイル時間 | 3,263 ms |
コンパイル使用メモリ | 220,516 KB |
最終ジャッジ日時 | 2025-01-22 09:12:05 |
ジャッジサーバーID (参考情報) |
judge5 / judge5 |
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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
//#define _GLIBCXX_DEBUG#include<bits/stdc++.h>using namespace std;#define endl '\n'#define lfs cout<<fixed<<setprecision(10)#define ALL(a) (a).begin(),(a).end()#define ALLR(a) (a).rbegin(),(a).rend()#define spa << " " <<#define fi first#define se second#define MP make_pair#define MT make_tuple#define PB push_back#define EB emplace_back#define rep(i,n,m) for(ll i = (n); i < (ll)(m); i++)#define rrep(i,n,m) for(ll i = (ll)(m) - 1; i >= (ll)(n); i--)using ll = long long;using ld = long double;const ll MOD1 = 1e9+7;const ll MOD9 = 998244353;const ll INF = 1e18;using P = pair<ll, ll>;template<typename T> using PQ = priority_queue<T>;template<typename T> using QP = priority_queue<T,vector<T>,greater<T>>;template<typename T1, typename T2>bool chmin(T1 &a,T2 b){if(a>b){a=b;return true;}else return false;}template<typename T1, typename T2>bool chmax(T1 &a,T2 b){if(a<b){a=b;return true;}else return false;}ll median(ll a,ll b, ll c){return a+b+c-max({a,b,c})-min({a,b,c});}void ans1(bool x){if(x) cout<<"Yes"<<endl;else cout<<"No"<<endl;}void ans2(bool x){if(x) cout<<"YES"<<endl;else cout<<"NO"<<endl;}void ans3(bool x){if(x) cout<<"Yay!"<<endl;else cout<<":("<<endl;}template<typename T1,typename T2>void ans(bool x,T1 y,T2 z){if(x)cout<<y<<endl;else cout<<z<<endl;}template<typename T1,typename T2,typename T3>void anss(T1 x,T2 y,T3 z){ans(x!=y,x,z);};template<typename T>void debug(const T &v,ll h,ll w,string sv=" "){for(ll i=0;i<h;i++){cout<<v[i][0];for(ll j=1;j<w;j++)cout<<sv<<v[i][j];cout<<endl;}};template<typename T>void debug(const T &v,ll n,string sv=" "){if(n!=0)cout<<v[0];for(ll i=1;i<n;i++)cout<<sv<<v[i];cout<<endl;};template<typename T>void debug(const vector<T>&v){debug(v,v.size());}template<typename T>void debug(const vector<vector<T>>&v){for(auto &vv:v)debug(vv,vv.size());}template<typename T>void debug(stack<T> st){while(!st.empty()){cout<<st.top()<<" ";st.pop();}cout<<endl;}template<typename T>void debug(queue<T> st){while(!st.empty()){cout<<st.front()<<" ";st.pop();}cout<<endl;}template<typename T>void debug(deque<T> st){while(!st.empty()){cout<<st.front()<<" ";st.pop_front();}cout<<endl;}template<typename T>void debug(PQ<T> st){while(!st.empty()){cout<<st.top()<<" ";st.pop();}cout<<endl;}template<typename T>void debug(QP<T> st){while(!st.empty()){cout<<st.top()<<" ";st.pop();}cout<<endl;}template<typename T>void debug(const set<T>&v){for(auto z:v)cout<<z<<" ";cout<<endl;}template<typename T>void debug(const multiset<T>&v){for(auto z:v)cout<<z<<" ";cout<<endl;}template<typename T,typename V>void debug(const map<T,V>&v){for(auto z:v)cout<<"["<<z.first<<"]="<<z.second<<",";cout<<endl;}template<typename T>vector<vector<T>>vec(ll x, ll y, T w){vector<vector<T>>v(x,vector<T>(y,w));return v;}ll gcd(ll x,ll y){ll r;while(y!=0&&(r=x%y)!=0){x=y;y=r;}return y==0?x:y;}vector<ll>dx={1,-1,0,0,1,1,-1,-1};vector<ll>dy={0,0,1,-1,1,-1,1,-1};template<typename T>vector<T> make_v(size_t a,T b){return vector<T>(a,b);}template<typename... Ts>auto make_v(size_t a,Ts... ts){return vector<decltype(make_v(ts...))>(a,make_v(ts...));}template<typename T1, typename T2>ostream &operator<<(ostream &os, const pair<T1, T2>&p){return os << p.first << " " << p.second;}template<typename T>ostream &operator<<(ostream &os, const vector<T> &v){for(auto &z:v)os << z << " ";cout<<"|"; return os;}template<typename T>void rearrange(vector<int>&ord, vector<T>&v){auto tmp = v;for(int i=0;i<tmp.size();i++)v[i] = tmp[ord[i]];}template<typename Head, typename... Tail>void rearrange(vector<int>&ord,Head&& head, Tail&&... tail){rearrange(ord, head);rearrange(ord, tail...);}template<typename T> vector<int> ascend(const vector<T>&v){vector<int>ord(v.size());iota(ord.begin(),ord.end(),0);sort(ord.begin(),ord.end(),[&](int i,int j){return v[i]<v[j];});return ord;}template<typename T> vector<int> descend(const vector<T>&v){vector<int>ord(v.size());iota(ord.begin(),ord.end(),0);sort(ord.begin(),ord.end(),[&](int i,int j){return v[i]>v[j];});return ord;}ll FLOOR(ll n,ll div){return n>=0?n/div:(n-div+1)/div;}ll CEIL(ll n,ll div){return n>=0?(n+div-1)/div:n/div;}template<typename T>T min(const vector<T>&v){return *min_element(v.begin(),v.end());}template<typename T>T max(const vector<T>&v){return *max_element(v.begin(),v.end());}template<typename T>T acc(const vector<T>&v){return accumulate(v.begin(),v.end(),T(0));};template<typename T>T reverse(const T &v){return T(v.rbegin(),v.rend());};//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());int popcount(ll x){return __builtin_popcountll(x);};int poplow(ll x){return __builtin_ctzll(x);};int pophigh(ll x){return 63 - __builtin_clzll(x);};template<typename T>T poll(queue<T> &q){auto ret=q.front();q.pop();return ret;};template<typename T>T poll(priority_queue<T> &q){auto ret=q.top();q.pop();return ret;};template<typename T>T poll(QP<T> &q){auto ret=q.top();q.pop();return ret;};template<typename T>T poll(stack<T> &s){auto ret=s.top();s.pop();return ret;};template< typename T = int >struct edge {int to;T cost;int id;edge():id(-1){};edge(int to, T cost = 1, int id = -1):to(to), cost(cost), id(id){}operator int() const { return to; }};template<typename T>using Graph = vector<vector<edge<T>>>;template<typename T>Graph<T> readGraph(int n,int m,int indexed=1,bool directed=false,bool weighted=false){Graph<T> ret(n);for(int es = 0; es < m; es++){int u,v;T w=1;cin>>u>>v;u-=indexed,v-=indexed;if(weighted)cin>>w;ret[u].emplace_back(v,w,es);if(!directed)ret[v].emplace_back(u,w,es);}return ret;}template<typename T>Graph<T> readParent(int n,int indexed=1,bool directed=true){Graph<T>ret(n);for(int i=1;i<n;i++){int p;cin>>p;p-=indexed;ret[p].emplace_back(i);if(!directed)ret[i].emplace_back(p);}return ret;}template<typename T>struct SCC{int n;const Graph<T>&G;vector<int>index;//各ノードが属する強連結成分の番号vector<int>start,visited,low,ord;int now_ord,group_num;SCC(const Graph<T> &g):G(g),n(g.size()){index.assign(n,-1);build();}void build(){low.assign(n,0);ord.assign(n,-1);index.assign(n,0);visited.reserve(n);now_ord=0,group_num=0;for(int i=0;i<n;i++){if(ord[i]==-1)dfs(i);}for(auto& x:index)x=group_num-1-x;}void dfs(int v){low[v]=ord[v]=now_ord++;visited.push_back(v);for(auto to:G[v]){if(ord[to]==-1){dfs(to);low[v]=min(low[v],low[to]);}else{low[v]=min(low[v],ord[to]);}}if(low[v]==ord[v]){while(1){int u=visited.back();visited.pop_back();ord[u]=n;index[u]=group_num;if(u==v)break;}group_num++;}}Graph<T>scc_graph;void build_edges(){scc_graph.resize(*max_element(index.begin(),index.end())+1);for(int i=0;i<n;i++){for(int j=0;j<G[i].size();j++){if(index[i]!=index[G[i][j]]){scc_graph[index[i]].emplace_back(index[G[i][j]], G[i][j].cost, G[i][j].id);}}}}vector<int>output(){return index;};};struct UnionFind {vector<ll> data;ll num;UnionFind(ll size) : data(size, -1) ,num(size){ }bool unite(ll x, ll y) {x = root(x); y = root(y);if (x != y) {if (data[y] < data[x]) swap(x, y);data[x] += data[y]; data[y] = x;num--;}return x != y;}bool find(ll x, ll y) {return root(x) == root(y);}ll root(ll x) {return data[x] < 0 ? x : data[x] = root(data[x]);}ll size(ll x) {return -data[root(x)];}};int main(){cin.tie(nullptr);ios_base::sync_with_stdio(false);ll res=0,buf=0;bool judge = true;ll n,m;cin>>n>>m;Graph<int>g(n);UnionFind uf(n);rep(i,0,m){ll u,v;cin>>u>>v;u--;v--;g[u].EB(v);uf.unite(u,v);}SCC scc(g);auto &idx=scc.index;ll scsz=max(idx)+1;vector<ll>cnt(scsz);rep(i,0,n)cnt[idx[i]]++;vector<bool>dag(n,true);rep(i,0,n){if(cnt[idx[i]]>=2)dag[uf.root(i)]=false;}vector<vector<ll>>v(n);rep(i,0,n){v[uf.root(i)].PB(i);}vector<P>ret;rep(i,0,n){if(v[i].empty())continue;if(dag[i]){sort(ALL(v[i]),[&](ll x,ll y){return idx[x]<idx[y];});rep(j,0,v[i].size()-1)ret.EB(v[i][j]+1,v[i][j+1]+1);}else{rep(j,0,v[i].size()){ret.EB(v[i][j]+1,v[i][(j+1)%v[i].size()]+1);}}}cout<<ret.size()<<endl;for(auto z:ret)cout<<z<<endl;return 0;}