結果

問題 No.274 The Wall
コンテスト
ユーザー Taiki0715
提出日時 2024-11-01 22:12:21
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 8 ms / 2,000 ms
コード長 6,850 bytes
コンパイル時間 6,266 ms
コンパイル使用メモリ 334,004 KB
実行使用メモリ 7,328 KB
最終ジャッジ日時 2025-03-17 19:13:52
合計ジャッジ時間 7,354 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 4
other AC * 23
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
#endif
using ll=long long;
using ull=unsigned long long;
using P=pair<ll,ll>;
template<typename T>using minque=priority_queue<T,vector<T>,greater<T>>;
template<typename T>bool chmax(T &a,const T &b){return (a<b?(a=b,true):false);}
template<typename T>bool chmin(T &a,const T &b){return (a>b?(a=b,true):false);}
template<typename T1,typename T2>istream &operator>>(istream &is,pair<T1,T2>&p){is>>p.first>>p.second;return is;}
template<typename T>istream &operator>>(istream &is,vector<T> &a){for(auto &i:a)is>>i;return is;}
template<typename T1,typename T2>void operator++(pair<T1,T2>&a,int n){a.first++,a.second++;}
template<typename T1,typename T2>void operator--(pair<T1,T2>&a,int n){a.first--,a.second--;}
template<typename T>void operator++(vector<T>&a,int n){for(auto &i:a)i++;}
template<typename T>void operator--(vector<T>&a,int n){for(auto &i:a)i--;}
#define reps(i,a,n) for(int i=(a);i<int(n);i++)
#define rep(i,n) reps(i,0,n)
#define all(x) x.begin(),x.end()
#define pcnt(x) __builtin_popcountll(x)
#define fin(x) return cout<<x<<'\n',static_cast<void>(0)
ll myceil(ll a,ll b){return (a+b-1)/b;}
template<typename T,size_t n,size_t id=0>
auto vec(const int (&d)[n],const T &init=T()){
  if constexpr (id<n)return vector(d[id],vec<T,n,id+1>(d,init));
  else return init;
}
#ifdef LOCAL
#include<debug.h>
#else
#define debug(...) static_cast<void>(0)
#define debugg(...) static_cast<void>(0)
template<typename T1,typename T2>ostream &operator<<(ostream &os,const pair<T1,T2>&p){os<<p.first<<' '<<p.second;return os;}
#endif
void SOLVE();
int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout<<fixed<<setprecision(16);
  #ifdef LOCAL
  clock_t start=clock();
  #endif
  int testcase=1;
  //cin>>testcase;
  for(int i=0;i<testcase;i++){
    SOLVE();
  }
  #ifdef LOCAL
  cerr<<"time:";
  cerr<<(clock()-start)/1000;
  cerr<<"ms\n";
  #endif
}
template<typename T=int>
struct Edge{
  int from,to;
  T weight;
  int index;
  Edge(int from_,int to_,T weight_=T(),int index_=-1):from(from_),to(to_),weight(weight_),index(index_){}
  Edge():from(-1),to(-1),weight(),index(-1){}
  friend std::ostream &operator<<(std::ostream &os,const Edge&e){
    os<<'[';
    os<<"from:"<<e.from;
    os<<"to:"<<e.to;
    os<<"weight:"<<e.weight;
    os<<"index:"<<e.index;
    os<<']';
    return os;
  }
};
using namespace std;
template<typename T=int>
struct Graph{
private:
  int n;
  vector<Edge<T>>edge;
  vector<Edge<T>>g;
  vector<int>ptr;
  bool directed;
  struct graph_range{
    using iterator=typename vector<Edge<T>>::iterator;
    iterator l,r;
    iterator begin()const{return l;}
    iterator end()const{return r;}
    int size()const{return r-l;}
    Edge<T> &operator[](int i)const{return l[i];}
  };
  struct const_graph_range{
    using iterator=typename vector<Edge<T>>::const_iterator;
    iterator l,r;
    iterator begin()const{return l;}
    iterator end()const{return r;}
    int size()const{return r-l;}
    const Edge<T> &operator[](int i)const{return l[i];}
  };
public:
  Graph(int n_,bool dir_):n(n_),directed(dir_){}
  Graph():n(0){}
  Graph(int n_,bool dir_,const vector<Edge<T>>&e):n(n_),directed(dir_),edge(e){build();}
  template<bool weighted=false,bool index=1>
  void read(int m){
    edge.reserve(m);
    for(int i=0;i<m;i++){
      int u,v;
      cin>>u>>v;
      T w;
      if constexpr(index)u--,v--;
      if constexpr(weighted)cin>>w;
      else w=1;
      edge.emplace_back(u,v,w,i);
    }
    build();
  }
  void add_edge(int u,int v){
    int id=edge.size();
    edge.emplace_back(u,v,1,id);
  }
  void add_edge(int u,int v,T w){
    int id=edge.size();
    edge.emplace_back(u,v,w,id);
  }
  void add_edge(int u,int v,T w,int index){
    edge.emplace_back(u,v,w,index);
  }
  void build(){
    vector<int>cnt(n+1,0);
    for(const Edge<T>&e:edge){
      cnt[e.from+1]++;
      if(!directed)cnt[e.to+1]++;
    }
    for(int i=1;i<=n;i++)cnt[i]+=cnt[i-1];
    ptr=cnt;
    g.resize(cnt[n]);
    for(const Edge<T>&e:edge){
      g[cnt[e.from]++]=e;
      if(!directed)g[cnt[e.to]++]=Edge<T>(e.to,e.from,e.weight,e.index);
    }
  }
  void reverse(){
    if(directed){
      for(Edge<T>&e:edge)swap(e.from,e.to);
      build();
    }
  }
  inline void to_directed(){
    directed=true;
    build();
  }
  inline void to_undirected(){
    directed=false;
    build();
  }
  void reserve(int m){edge.reserve(m);}
  graph_range operator[](int i){return graph_range{g.begin()+ptr[i],g.begin()+ptr[i+1]};}
  const_graph_range operator[](int i)const{return const_graph_range{g.begin()+ptr[i],g.begin()+ptr[i+1]};}
  const Edge<T>& get_edge(int i)const{return edge[i];}
  inline bool is_directed()const{return directed;}
  inline int size()const{return n;}
  inline int edge_size()const{return edge.size();}
};
template<typename T>
vector<int>strongly_connected_components(Graph<T>g){
  int n=g.size();
  vector<bool>seen(n,false);
  vector<int>st(g.edge_size()+1);
  int p=0;
  vector<int>vis;
  vis.reserve(n);
  for(int i=0;i<n;i++)if(!seen[i]){
    st[p++]=i;
    while(p>0){
      int x=st[--p];
      if(x<0){
        vis.push_back(~x);
        continue;
      }
      if(seen[x])continue;
      seen[x]=true;
      st[p++]=~x;
      for(const Edge<T>&e:g[x])if(!seen[e.to])st[p++]=e.to;
    }
  }
  vector<int>scc(n,-1);
  g.reverse();
  int sp=0;
  for(int i=n-1;i>=0;i--)if(scc[vis[i]]==-1){
    st[p++]=vis[i];
    while(p>0){
      int x=st[--p];
      scc[x]=sp;
      for(const Edge<T>&e:g[x])if(scc[e.to]==-1)st[p++]=e.to;
    }
    sp++;
  }
  return scc;
}
using namespace std;
vector<int>two_sat(int n,const vector<pair<int,int>>&a){
  Graph<int>g(n*2,true);
  g.reserve(a.size()*2);
  for(const auto&[u,v]:a){
    if(u>=0&&v>=0){
      g.add_edge(u+n,v);
      g.add_edge(v+n,u);
    }
    else if(u>=0){
      g.add_edge(u+n,(~v)+n);
      g.add_edge(~v,u);
    }
    else if(v>=0){
      g.add_edge(~u,v);
      g.add_edge(v+n,(~u)+n);
    }
    else{
      g.add_edge(~u,(~v)+n);
      g.add_edge(~v,(~u)+n);
    }
  }
  g.build();
  vector<int>scc=strongly_connected_components(g);
  vector<int>ret(n);
  for(int i=0;i<n;i++){
    if(scc[i]==scc[i+n])return vector<int>{};
    ret[i]=scc[i]>scc[i+n];
  }
  return ret;
}
void SOLVE(){
  int n,m;
  cin>>n>>m;
  vector<pair<int,int>>a(n);
  rep(i,n){
    cin>>a[i];
    a[i].second++;
  }
  vector<pair<int,int>>b;
  rep(i,n-1)reps(j,i+1,n){
    bool f=max(a[i].first,a[j].first)>=min(a[i].second,a[j].second);
    bool g=max(a[i].first,m-a[j].second)>=min(a[i].second,m-a[j].first);
    if(f&&g)continue;
    else if(!f&&!g)fin("NO");
    else if(f){
      b.push_back({~i,j});
      b.push_back({i,~j});
    }
    else{
      b.push_back({i,j});
      b.push_back({~i,~j});
    }
  }
  cout<<(two_sat(n,b).size()?"YES":"NO")<<endl;
}
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