제출 #931382

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
931382		alexander707070	Construction of Highway (JOI18_construction)	C++14	16 / 100	2021 ms	32416 KiB

construction

#include<bits/stdc++.h>
#define MAXN 200007
using namespace std;

const int inf=1e9+7;

int n,c[MAXN],a[MAXN],b[MAXN],sz[MAXN],heavy[MAXN],parent[MAXN];
int pos[MAXN],head[MAXN],tt,lazy[4*MAXN],dep[MAXN];
pair<int,int> tree[4*MAXN],curr;

vector<int> v[MAXN];
vector< pair<int,int> > w;

void dfs(int x,int p,int d){

    parent[x]=p; dep[x]=d;
    sz[x]=1;

    for(int i=0;i<v[x].size();i++){
        if(v[x][i]==p)continue;
        dfs(v[x][i],x,d+1);
        if(sz[v[x][i]]>sz[heavy[x]])heavy[x]=v[x][i];

        sz[x]+=sz[v[x][i]];
    }
}

void decompose(int x,int p,int h){
    tt++; pos[x]=tt; head[x]=h;

    if(heavy[x]!=0){
        decompose(heavy[x],x,h);
    }

    for(int i=0;i<v[x].size();i++){
        if(v[x][i]==p or v[x][i]==heavy[x])continue;
        decompose(v[x][i],x,v[x][i]);
    }
}

void psh(int v){
    if(lazy[v]==0)return;

    tree[2*v].first=tree[2*v].second=lazy[v];
    tree[2*v+1].first=tree[2*v+1].second=lazy[v];

    lazy[2*v]=lazy[2*v+1]=lazy[v];

    lazy[v]=0;
}

pair<int,int> combine(pair<int,int> fr,pair<int,int> sc){
    return {min(fr.first,sc.first),max(fr.second,sc.second)};
}

void update(int v,int l,int r,int ll,int rr,int val){
    if(ll>rr)return;
    if(l==ll and r==rr){
        tree[v].first=tree[v].second=val;
        lazy[v]=val;
    }else{
        psh(v);
        int tt=(l+r)/2;
        update(2*v,l,tt,ll,min(tt,rr),val);
        update(2*v+1,tt+1,r,max(tt+1,ll),rr,val);

        tree[v]=combine(tree[2*v],tree[2*v+1]);
    }
}

pair<int,int> info(int v,int l,int r,int ll,int rr){
    if(ll>rr)return{inf,0};

    if(l==ll and r==rr){
        return tree[v];
    }else{
        psh(v);
        int tt=(l+r)/2;
        return combine( info(2*v,l,tt,ll,min(tt,rr)) , info(2*v+1,tt+1,r,max(tt+1,ll),rr) );
    }
}

void upgrade(int x,int val){
    while(x!=0){
        update(1,1,n,pos[head[x]],pos[x],val);
        x=parent[head[x]];
    }
}

void add_segments(int l,int r){

    while(r>=l){
        int ll=l-1,rr=r,mid;
        while(ll+1<rr){
            mid=(ll+rr)/2;

            curr=info(1,1,n,mid,r);
            if(curr.first==curr.second){
                rr=mid;
            }else{
                ll=mid;
            }
        }

        curr=info(1,1,n,rr,r);
        w.push_back({curr.first,r-rr+1});
        r=rr-1;
    }
}

long long query(int x){
    long long ans=0;

    w.clear();

    while(x!=0){
        add_segments(pos[head[x]],pos[x]);
        x=parent[head[x]];
    }

    for(int i=0;i<w.size();i++){
        for(int f=i+1;f<w.size();f++){
            if(w[i].first<w[f].first)ans+=(long long) w[i].second*w[f].second;
        }
    }

    return ans;
}

int main(){

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>c[i];
    }

    for(int i=1;i<=n-1;i++){
        cin>>a[i]>>b[i];
        v[a[i]].push_back(b[i]);
        v[b[i]].push_back(a[i]);
    }

    dfs(1,0,1);
    decompose(1,0,1);

    for(int i=1;i<=n;i++){
        update(1,1,n,pos[i],pos[i],c[i]);
    }

    for(int i=1;i<=n-1;i++){
        cout<<query(a[i])<<"\n";
        upgrade(b[i],c[b[i]]);
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

construction.cpp: In function 'void dfs(int, int, int)':
construction.cpp:19:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for(int i=0;i<v[x].size();i++){
      |                 ~^~~~~~~~~~~~
construction.cpp: In function 'void decompose(int, int, int)':
construction.cpp:35:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     for(int i=0;i<v[x].size();i++){
      |                 ~^~~~~~~~~~~~
construction.cpp: In function 'long long int query(int)':
construction.cpp:121:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  121 |     for(int i=0;i<w.size();i++){
      |                 ~^~~~~~~~~
construction.cpp:122:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |         for(int f=i+1;f<w.size();f++){
      |                       ~^~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 0 / 84