test/aoj/2790.test.cpp

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Last update: 2020-10-27 19:32:25+09:00
Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2790

Depends on

Code

#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2790"

#include<bits/stdc++.h>
using namespace std;

#define call_from_test
#include "../../tools/chminmax.cpp"
#include "../../tools/fixpoint.cpp"
#include "../../tree/centroid.cpp"
#undef call_from_test

#ifdef SANITIZE
#define IGNORE
#endif

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  int n;
  cin>>n;
  vector<int> gs(n);
  for(int i=0;i<n;i++) cin>>gs[i];
  using P = pair<int, int>;
  vector< vector<P> > G(n);
  Centroid C(n);
  for(int i=1;i<n;i++){
    int a,b,d;
    cin>>a>>b>>d;
    a--;b--;
    G[a].emplace_back(b,d);
    G[b].emplace_back(a,d);
    C.add_edge(a,b);
  }

  int ans=1;
  queue<int> que;
  que.emplace(0);
  while(!que.empty()){
    int rt=C.build(que.front())[0];
    que.pop();
    for(int uku=0;uku<2;uku++){
      int len=0;
      MFP([&](auto dfs,int v,int p,int d)->void{
            chmax(len,d);
            for(auto e:G[v]){
              int u=e.first;
              if(u==p||!C.alive(u)) continue;
              dfs(u,v,d+1);
            }
          })(rt,-1,1);

      const int INF = 1e9;
      vector<int> dat(len+1,INF);
      dat[0]=-INF;
      for(auto e:G[rt]){
        int ch=e.first,cost=e.second;
        if(!C.alive(ch)) continue;
        // calc path
        MFP([&](auto dfs,int v,int p,int d,int sum,int val)->void{
              if(val>=0) chmax(ans,d+1);
              int k=--upper_bound(dat.begin(),dat.end(),val)-dat.begin();
              if(k) chmax(ans,k+1+d);
              for(auto e:G[v]){
                int u=e.first,c=e.second;
                if(u==p||!C.alive(u)) continue;
                dfs(u,v,d+1,sum-c+gs[u],min(val,sum-c));
              }
            })(ch,rt,1,gs[rt]-cost+gs[ch],gs[rt]-cost);

        // update dat
        MFP([&](auto dfs,int v,int p,int d,int sum,int val)->void{
              if(val>=0){
                chmin(dat[d],-sum);
                chmax(ans,d+1);
              }
              for(auto e:G[v]){
                int u=e.first,c=e.second;
                if(u==p||!C.alive(u)) continue;
                dfs(u,v,d+1,sum+(gs[u]-c),(val>0?0:val)+(gs[u]-c));
              }
              chmin(dat[d],dat[d+1]);
            })(ch,rt,1,gs[ch]-cost,gs[ch]-cost);
      }

      reverse(G[rt].begin(),G[rt].end());
    }
    C.disable(rt);
    for(int u:C.G[rt])
      if(C.alive(u)) que.emplace(u);
  }
  cout<<ans<<endl;
  return 0;
}

#line 1 "test/aoj/2790.test.cpp"
#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2790"

#include<bits/stdc++.h>
using namespace std;

#define call_from_test
#line 1 "tools/chminmax.cpp"

#line 3 "tools/chminmax.cpp"
using namespace std;
#endif
//BEGIN CUT HERE
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
//END CUT HERE
#ifndef call_from_test
signed main(){
  return 0;
}
#endif
#line 1 "tools/fixpoint.cpp"

#line 3 "tools/fixpoint.cpp"
using namespace std;
#endif
//BEGIN CUT HERE
template<typename F>
struct FixPoint : F{
  FixPoint(F&& f):F(forward<F>(f)){}
  template<typename... Args>
  decltype(auto) operator()(Args&&... args) const{
    return F::operator()(*this,forward<Args>(args)...);
  }
};
template<typename F>
inline decltype(auto) MFP(F&& f){
  return FixPoint<F>{forward<F>(f)};
}
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif
#line 1 "tree/centroid.cpp"

#line 3 "tree/centroid.cpp"
using namespace std;
#endif
//BEGIN CUT HERE
struct Centroid{
  vector<int> sz,dead;
  vector< vector<int> > G;
  Centroid(int n):sz(n,1),dead(n,0),G(n){}

  void add_edge(int u,int v){
    G[u].emplace_back(v);
    G[v].emplace_back(u);
  }

  int dfs(int v,int p){
    sz[v]=1;
    for(int u:G[v])
      if(u!=p and !dead[u]) sz[v]+=dfs(u,v);
    return sz[v];
  }

  void find(int v,int p,int tmp,vector<int> &cs) {
    int ok=1;
    for (int u:G[v]){
      if(u==p or dead[u]) continue;
      find(u,v,tmp,cs);
      ok&=(sz[u]<=tmp/2);
    }
    ok&=(tmp-sz[v]<=tmp/2);
    if(ok) cs.emplace_back(v);
  }

  vector<int> build(int r) {
    int tmp=dfs(r,-1);
    vector<int> cs;
    find(r,-1,tmp,cs);
    return cs;
  }

  const vector<int>& operator[](int k)const{return G[k];}
  void disable(int v){dead[v]=1;}
  void  enable(int v){dead[v]=0;}
  int alive(int v){return !dead[v];}
};
//END CUT HERE
#ifndef call_from_test
signed main(){
  return 0;
}
#endif
#line 10 "test/aoj/2790.test.cpp"
#undef call_from_test

#ifdef SANITIZE
#define IGNORE
#endif

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  int n;
  cin>>n;
  vector<int> gs(n);
  for(int i=0;i<n;i++) cin>>gs[i];
  using P = pair<int, int>;
  vector< vector<P> > G(n);
  Centroid C(n);
  for(int i=1;i<n;i++){
    int a,b,d;
    cin>>a>>b>>d;
    a--;b--;
    G[a].emplace_back(b,d);
    G[b].emplace_back(a,d);
    C.add_edge(a,b);
  }

  int ans=1;
  queue<int> que;
  que.emplace(0);
  while(!que.empty()){
    int rt=C.build(que.front())[0];
    que.pop();
    for(int uku=0;uku<2;uku++){
      int len=0;
      MFP([&](auto dfs,int v,int p,int d)->void{
            chmax(len,d);
            for(auto e:G[v]){
              int u=e.first;
              if(u==p||!C.alive(u)) continue;
              dfs(u,v,d+1);
            }
          })(rt,-1,1);

      const int INF = 1e9;
      vector<int> dat(len+1,INF);
      dat[0]=-INF;
      for(auto e:G[rt]){
        int ch=e.first,cost=e.second;
        if(!C.alive(ch)) continue;
        // calc path
        MFP([&](auto dfs,int v,int p,int d,int sum,int val)->void{
              if(val>=0) chmax(ans,d+1);
              int k=--upper_bound(dat.begin(),dat.end(),val)-dat.begin();
              if(k) chmax(ans,k+1+d);
              for(auto e:G[v]){
                int u=e.first,c=e.second;
                if(u==p||!C.alive(u)) continue;
                dfs(u,v,d+1,sum-c+gs[u],min(val,sum-c));
              }
            })(ch,rt,1,gs[rt]-cost+gs[ch],gs[rt]-cost);

        // update dat
        MFP([&](auto dfs,int v,int p,int d,int sum,int val)->void{
              if(val>=0){
                chmin(dat[d],-sum);
                chmax(ans,d+1);
              }
              for(auto e:G[v]){
                int u=e.first,c=e.second;
                if(u==p||!C.alive(u)) continue;
                dfs(u,v,d+1,sum+(gs[u]-c),(val>0?0:val)+(gs[u]-c));
              }
              chmin(dat[d],dat[d+1]);
            })(ch,rt,1,gs[ch]-cost,gs[ch]-cost);
      }

      reverse(G[rt].begin(),G[rt].end());
    }
    C.disable(rt);
    for(int u:C.G[rt])
      if(C.alive(u)) que.emplace(u);
  }
  cout<<ans<<endl;
  return 0;
}