結果

問題 No.1326 ふたりのDominator
コンテスト
ユーザー tute7627
提出日時 2021-02-01 17:30:06
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 140 ms / 2,000 ms
コード長 10,987 bytes
コンパイル時間 3,290 ms
コンパイル使用メモリ 235,968 KB
最終ジャッジ日時 2025-01-18 10:37:13
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 * 1
other AC * 24
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 # 

//#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 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 T>void debug(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(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>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<ll>&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<ll>&ord,Head&& head, Tail&&... tail){
  rearrange(ord, head);
  rearrange(ord, tail...);
}
//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 = int >
struct edge {
  int to;
  T cost;
  int id;
  edge() = default;
  edge(int to, T cost = 1, int id = 0):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,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 Lowlink{
  Graph<T> G;
  int size;
  vector<int>ord,low,used;
  vector<int>articulation;
  vector<pair<int,int>>bridge;
  Lowlink(Graph<T> &g):G(g){
    size = G.size();
    ord.assign(size,-1);
    low.assign(size,-1);
    used.assign(size,0);
    int tmp=0;
    for(int i=0;i<size;i++){
      if(!used[i]){
        dfs(i,tmp,-1);
      }
    }
  }
  void dfs(int k,int &num,int par){
    ord[k] = num;
    low[k] = num;
    num++;
    used[k] = 1;
    int cnt=0;
    bool is_articulation=false;
    bool multiple=false;
    for(int i=0;i<G[k].size();i++){
      if(!multiple&&par==G[k][i]){
        multiple=true;
        continue;
      }
      if(used[G[k][i]]){
        chmin(low[k],ord[G[k][i]]);
      }
      else{
        cnt++;
        dfs(G[k][i],num,k);
        chmin(low[k],low[G[k][i]]);
        if(ord[k]<low[G[k][i]])bridge.emplace_back(k,G[k][i]);
        if(ord[k]<=low[G[k][i]]&&par!=-1)is_articulation=true;
      }
    }
    if(par==-1&&cnt>=2)is_articulation=true;
    if(is_articulation)articulation.push_back(k);
    return; 
  }
  vector<int>tecc_index;//二重辺連結成分の番号
  Graph<T>tecc_graph;
  int TECC(){
    tecc_index.assign(G.size(),-1);
    int cnt=0;
    for(int i=0;i<size;i++){
      if(tecc_index[i]==-1)dfs_tecc(i,-1,cnt);
    }
    tecc_graph.assign(cnt+1,vector<edge<T>>());
    for(int i=0;i<bridge.size();i++){
      int u=tecc_index[bridge[i].fi],v=tecc_index[bridge[i].se];
      tecc_graph[u].emplace_back(v);
      tecc_graph[v].emplace_back(u);
    }
    return *max_element(tecc_index.begin(),tecc_index.end())+1;
  }
  void dfs_tecc(int k,int par,int &group){
    if(par==-1||ord[par]<low[k]){
      tecc_index[k] = group++;
    }
    else tecc_index[k] = tecc_index[par];
    for(int i=0;i<G[k].size();i++){
      if(tecc_index[G[k][i]]==-1)dfs_tecc(G[k][i],k,group);
    }
  }
  vector<vector<pair<int, int>>>bcc;
  stack<pair<int, int>>tmp;
  void BCC(){
    used.assign(G.size(), false);
    for(int i=0;i<G.size();i++){
      if(!used[i]){
        dfs_bcc(i, -1);
      }
    }
  }
  void dfs_bcc(int k, int par){
    used[k]=true;
    for(int to:G[k]){
      if(to==par)continue;
      if(!used[to] | ord[to] < ord[k]){
        tmp.emplace(minmax(k, to));
      }
      if(!used[to]){
        dfs_bcc(to, k);
        if(low[to] >= ord[k]){
          bcc.emplace_back();
          while(1){
            auto e = tmp.top();
            bcc.back().emplace_back(e);
            tmp.pop();
            if(e.first == min(k, to) && e.second == max(k, to))break;
          }
        }
      }
    }
  }
  Graph<T>bct_graph;
  vector<int>bct_index;
  vector<bool>art;
  void makeBCT(){
    assert(bcc.empty());
    BCC();
    art.assign(G.size(), false);
    bct_index.assign(G.size(), -1);
    for(auto v:articulation){
      bct_index[v] = bct_graph.size();
      bct_graph.emplace_back();
      art[v] = true;
    }
    vector<bool>check(G.size(),false);
    for(auto &ev:bcc){
      int idx = bct_graph.size();
      bct_graph.emplace_back();
      queue<int>rev;
      for(auto &e:ev){
        for(auto &v:{e.first, e.second}){
          if(art[v]&&!check[v]){
            rev.push(v);
            check[v] = true;
            bct_graph[idx].emplace_back(bct_index[v]);
            bct_graph[bct_index[v]].emplace_back(idx);
          }
          else if(!art[v]){
            bct_index[v] = idx;
          }
        }
      }
      while(!rev.empty()){
        check[rev.front()] = false;
        rev.pop();
      }
    }
  }
};
template<typename T>
struct HLD{
  int n;
  vector<int>sz;//部分木サイズ
  vector<long long>dep;
  vector<int>par;
  vector<int>head;
  Graph<T> &g;//隣接リスト
  vector<edge<T>>edges;//データ構造に乗せるedge列
  vector<int>in,out;//[in,out)で部分木、[ina,inb]でa~bのパス(aが上)
  vector<int>comp;//連結成分の根
  //inは頂点のindexを表す。また、edge列の下側の頂点である
  HLD(Graph<T> &g,int r=-1):g(g),n(g.size()){
    hld_build(r);
  }
  void hld_build(int root = -1){
    in.assign(n,-1);out.assign(n,-1);dep.assign(n,0);
    par.assign(n,-1);head.assign(n,-1);sz.assign(n,-1);comp.assign(n,-1);
    edges.assign(n,edge<T>());
    if(root == -1){//根がどこでも良い場合(森でも可)
      for(int i=0;i<n;i++){
        if(sz[i] == -1){
          head[i] = i;
          dfs_sz(i, 0, i);
          dfs_hld(i);
        }
      }
    }
    else{
      head[root] = root;
      dfs_sz(root, 0, root);
      dfs_hld(root);
    }
  }
  void dfs_sz(int k, long long d,int r){
    sz[k] = 1;
    comp[k] = r;
    for(auto &e: g[k]){
      if(e.to == par[k])continue;
      par[e.to] = k;
      dfs_sz(e.to, d+e.cost, r);
      sz[k] += sz[e.to];
      if(sz[e.to] > sz[g[k][0].to])swap(e, g[k][0]);
    }
  }
  int time = 0;
  void dfs_hld(int k){
    in[k] = time++;
    for(auto e:g[k]){
      if(e.to == par[k])continue;
      head[e.to] = (e.to == g[k][0].to ? head[k]: e.to);
      edges[time] = e;
      dfs_hld(e.to);
    }
    out[k] = time;
  }
  int lca(int p,int q){
    while(1){
      if(in[p] < in[q])swap(p,q);
      if(head[p] == head[q])return q;
      p = par[head[p]];
    }
  }
  vector<pair<int,int>>query_path(int p,int q,bool isEdge){
    int r=lca(p,q);
    vector<pair<int,int>>ret;
    for(int i=0;i<2;i++){
      if(i == 1)swap(p,q);
      while(1){
        if(isEdge&&p==r)break;
        if(head[p]==head[r]){
          ret.emplace_back(in[r]+(isEdge?1:i),in[p]+1);
          break;
        }
        ret.emplace_back(in[head[p]],in[p]+1);
        p = par[head[p]];
      }
    }
    return ret;
  }
  vector<vector<pair<int,int>>>query_order_path(int p,int q,bool isEdge){
	//非可換クエリ用、配列0を順番を反転したデータ構造に、配列1を通常のデータ構造に
    vector<vector<pair<int,int>>>ret(2);
    int r=lca(p,q);
    for(int i=0;i<2;i++){
      if(i == 1)swap(p,q);
      while(1){
        if(isEdge&&p==r)break;
        if(head[p]==head[r]){
          if(i==0) ret[i].emplace_back(n-(in[p]+1),n-(in[r]+(isEdge?1:i)));
          else ret[i].emplace_back(in[r]+(isEdge?1:i),in[p]+1);
          break;
        }
        if(i==0) ret[i].emplace_back(n-(in[p]+1),n-(in[head[p]]));
        else ret[i].emplace_back(in[head[p]],in[p]+1);
        p = par[head[p]];
      }
    }
    reverse(ret[1].begin(), ret[1].end());
    return ret;
  }
  pair<int,int>query_subtree(int p,bool isEdge){
    return make_pair(in[p]+isEdge,out[p]);
  }
  //uのv方向の子 子孫関係は前もって確認すること(in,outを見る)
  int child(int u,int v){
    while(1){
      if(head[u]==head[v]){
        v=g[u][0].to;
        break;
      }
      v=head[v];
      if(par[v]==u)break;
      v=par[v];
    }
    return v;
  }
  long long dist(int u,int v){
    return dep[u]+dep[v]-2*dep[lca(u,v)];
  }
};
int main(){
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  ll res=0,buf=0;
  bool judge = true;
  int n,m;cin>>n>>m;
  auto g=readGraph<int>(n,m);
  Lowlink low(g);
  low.makeBCT();
  auto bct=low.bct_graph;
  auto idx=low.bct_index;
  ll sz=bct.size();
  HLD hld(bct);
  vector<ll>a(sz+1);
  for(auto z:low.articulation)a[hld.in[idx[z]]+1]=1;
  rep(i,0,sz)a[i+1]+=a[i];
  ll q;cin>>q;
  while(q--){
    ll c,d;cin>>c>>d;c--;d--;
    ll ret=-(ll)low.art[c]-(ll)low.art[d];
    auto tmp=hld.query_path(idx[c],idx[d],false);
    for(auto z:tmp){
      ret+=a[z.se]-a[z.fi];
    }
    cout<<max(0LL,ret)<<endl;
  }
  return 0;
}
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