Submission #543557

#	Time	Username	Problem	Language	Result	Execution time	Memory
543557		new_acc	Road Closures (APIO21_roads)	C++14	100 / 100	309 ms	45744 KiB

roads

#include<bits/stdc++.h>
#define fi first
#define se second
#define pitem item*
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=1e5+10;
const ll INF=1e14;
struct item{
    item *l,*r;
    int val,il,pod,prior;
    ll sum;
};
pitem tr[N];
mt19937 rng(1);
int oj[N],fau[N],kk[N],dep[N],kr[N];
ll dp[N][2];
vector<pair<int,int> >graf[N];
vector<pair<int,int> >graf2[N];
vi aa[N];
bitset<N>bb,vis;
int Find(int a){
    if(fau[a]==a) return a;
    return fau[a]=Find(fau[a]);
}
void Union(int a,int b){
    a=Find(a),b=Find(b);
    if(dep[kk[a]]<dep[kk[b]]) swap(a,b);
    fau[a]=b;
}
void comb(pitem v){
    v->sum=(v->l!=nullptr?v->l->sum:0)+(v->r!=nullptr?v->r->sum:0)+(ll)(v->val)*(ll)(v->il);
    v->pod=(v->l!=nullptr?v->l->pod:0)+(v->r!=nullptr?v->r->pod:0)+(v->il);
} 
pair<pitem,pitem> split(pitem v,int x){
    if(!v) return {nullptr,nullptr};
    if((v->val)<=x){
        pair<pitem,pitem>curr=split(v->r,x);
        v->r=curr.fi;
        comb(v);
        return {v,curr.se};
    }else{
        pair<pitem,pitem>curr=split(v->l,x);
        v->l=curr.se;
        comb(v);
        return {curr.fi,v};
    }
}
pitem merge(pitem v1,pitem v2){
    if(!v1 or !v2) return (!v1?v2:v1);
    if((v1->prior)>(v2->prior)){
        v1->r=merge(v1->r,v2);
        comb(v1);
        return v1;
    }else{
        v2->l=merge(v1,v2->l);
        comb(v2);
        return v2;
    }
}
pitem add(pitem v,int x){
    pair<pitem,pitem>curr1=split(v,x);
    pair<pitem,pitem>curr2=split(curr1.fi,x-1);
    if(!curr2.se){
        pitem nn=new item;
        nn->val=x,nn->pod=1,nn->prior=uniform_int_distribution<int>(1,1000*1000*1000)(rng);
        nn->sum=x,nn->il=1,nn->l=nullptr,nn->r=nullptr;
        v=merge(merge(curr2.fi,nn),curr1.se);
        return v;
    }
    curr2.se->pod++,curr2.se->il++,curr2.se->sum+=x;
    v=merge(merge(curr2.fi,curr2.se),curr1.se);
    return v;
}
pitem del(pitem v,int x){
    pair<pitem,pitem>curr1=split(v,x);
    pair<pitem,pitem>curr2=split(curr1.fi,x-1);
    if(curr2.se!=nullptr){
        curr2.se->il--;
        curr2.se->pod--,curr2.se->sum-=x,curr2.se;
    }
    if(!curr2.se or curr2.se->il==0){
    	if(curr2.se!=nullptr) delete curr2.se;
        v=merge(curr2.fi,curr1.se);
        return v;
    }
    curr1.fi=merge(curr2.fi,curr2.se);
    v=merge(curr1.fi,curr1.se);
    return v;
}
ll sum(pitem v,int x){
    if(!v or x==0) return 0;
    ll suml=(v->sum)-(!(v->r)?0:v->r->sum);
    int pp=(v->pod)-(!(v->r)?0:v->r->pod);
    if(pp<=x) return sum(v->r,x-pp)+suml;
    else{
        int wz=max(0,x-(!(v->l)?0:v->l->pod));
        return sum(v->l,x-wz)+(ll)(v->val)*(ll)wz;
    }
}
void dfsi(int v,int o){
    oj[v]=o;
    dep[v]=dep[o]+1;
    for(auto [u,c]:graf[v]){
        if(u==o) continue;
        tr[v]=add(tr[v],c);
        kr[u]=c;
        dfsi(u,v);
    }
}
ll ob(vl pom,int v,int usu){
    ll res=0,res2=INF;
    int g=0;
    for(int i=0;i<pom.size();i++){
        if(pom[i]>0) break;
        res+=pom[i],usu--;
        g++;
    }
    if(usu>0){
        if((!tr[v]?0:(tr[v]->pod))>=usu) res2=sum(tr[v],usu);
        ll curr=0;
        for(int i=g;i<pom.size();i++){
            curr+=pom[i];
            usu--;
            usu=max(0,usu);
            if((!tr[v]?0:(tr[v]->pod))>=usu) res2=min(res2,curr+sum(tr[v],usu));
        }
        return res+res2;

    }else return res;
}
void dfs(int v,int o,int x){
    vl pom;
    ll res=0;
    int aktx=x;
    for(auto [u,c]:graf2[v]){
        if(o==u) continue;
        dfs(u,v,x);
        if(dp[u][0]!=INF){
            pom.push_back(dp[u][1]-dp[u][0]);
            res+=dp[u][0];
        }else{
            res+=dp[u][1];
            aktx++;
        }
    }
    sort(pom.begin(),pom.end());
    dp[v][0]=ob(pom,v,graf[v].size()-aktx)+res;
    dp[v][1]=ob(pom,v,graf[v].size()-(aktx+1))+res+kr[v];
    dp[v][0]=min(dp[v][0],INF),dp[v][1]=min(dp[v][1],INF);
}
vl minimum_closure_costs(int n,vi u,vi v,vi w){
    ll xd=0;
    for(int i=0;i<n-1;i++){
        u[i]++,v[i]++;
        graf[u[i]].push_back({v[i],w[i]}),graf[v[i]].push_back({u[i],w[i]});
    }
    for(int i=1;i<=n;i++) fau[i]=i,kk[i]=i;
    dfsi(1,1);
    kr[1]=1e9;
    for(int i=1;i<=n;i++) aa[graf[i].size()].push_back(i);
    /*for(int i=1;i<=n;i++){
        for(auto [u,c]:graf[i]){
            graf2[i].push_back({u,c});
            if(oj[i]!=u) tr[i]=del(tr[i],c);
        }
    }*/
    vl res(n);
    vi k;
    for(int i=n-1;i>=0;i--){
        for(auto v:aa[i]){
            for(auto [u,c]:graf[v]){
                if(bb[u]){
                    Union(v,u);
                    graf2[u].push_back({v,c}),graf2[v].push_back({u,c});
                    if(oj[v]!=u) tr[v]=del(tr[v],c);
                    if(oj[u]!=v) tr[u]=del(tr[u],c);
                 }
            }
            k.push_back(v);
            bb[v]=1;
        }
        ll ans=0;
        for(auto u:k){
            if(vis[Find(u)]) continue;
            vis[Find(u)]=1;
            dfs(kk[Find(u)],kk[Find(u)],i);
            ans+=min(dp[kk[Find(u)]][0],dp[kk[Find(u)]][1]);
        }
        for(auto u:k) vis[Find(u)]=0;
        res[i]=ans;
    }
    return res;
}

Compilation message (stderr)

roads.cpp: In function 'item* del(item*, int)':
roads.cpp:3:12: warning: right operand of comma operator has no effect [-Wunused-value]
    3 | #define se second
      |            ^
roads.cpp:82:48: note: in expansion of macro 'se'
   82 |         curr2.se->pod--,curr2.se->sum-=x,curr2.se;
      |                                                ^~
roads.cpp: In function 'void dfsi(int, int)':
roads.cpp:106:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  106 |     for(auto [u,c]:graf[v]){
      |              ^
roads.cpp: In function 'll ob(vl, int, int)':
roads.cpp:116:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |     for(int i=0;i<pom.size();i++){
      |                 ~^~~~~~~~~~~
roads.cpp:124:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |         for(int i=g;i<pom.size();i++){
      |                     ~^~~~~~~~~~~
roads.cpp: In function 'void dfs(int, int, int)':
roads.cpp:138:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  138 |     for(auto [u,c]:graf2[v]){
      |              ^
roads.cpp: In function 'vl minimum_closure_costs(int, vi, vi, vi)':
roads.cpp:174:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  174 |             for(auto [u,c]:graf[v]){
      |                      ^
roads.cpp:155:8: warning: unused variable 'xd' [-Wunused-variable]
  155 |     ll xd=0;
      |        ^~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 17 / 17
• Subtask 6: 25 / 25
• Subtask 7: 22 / 22