Submission #931386

#	Time	Username	Problem	Language	Result	Execution time	Memory
931386		alexander707070	Construction of Highway (JOI18_construction)	C++14	100 / 100	775 ms	33220 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],cnt;
int pos[MAXN],head[MAXN],tt,lazy[4*MAXN],dep[MAXN];
pair<int,int> tree[4*MAXN],curr;

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

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;
    }
}

int fenwick[MAXN];

void add(int pos,int val){
    while(pos<=cnt){
        fenwick[pos]+=val;
        pos+=(pos & (-pos));
    }
}

int getsum(int pos){
    int res=0;
    while(pos>=1){
        res+=fenwick[pos];
        pos-=(pos & (-pos));
    }
    return res;
}

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++){
        ans+=(long long) getsum(w[i].first-1)*w[i].second;
        add(w[i].first,w[i].second);
    }

    for(int i=0;i<w.size();i++){
        add(w[i].first,-w[i].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];
        s.push_back(c[i]);
    }

    sort(s.begin(),s.end());
    for(int i=0;i<s.size();i++){
        if(i==0 or s[i]!=s[i-1])cnt++;
        mp[s[i]]=cnt;
    }

    for(int i=1;i<=n;i++)c[i]=mp[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;
}

Compilation message (stderr)

construction.cpp: In function 'void dfs(int, int, int)':
construction.cpp:20:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for(int i=0;i<v[x].size();i++){
      |                 ~^~~~~~~~~~~~
construction.cpp: In function 'void decompose(int, int, int)':
construction.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i=0;i<v[x].size();i++){
      |                 ~^~~~~~~~~~~~
construction.cpp: In function 'long long int query(int)':
construction.cpp:140:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  140 |     for(int i=0;i<w.size();i++){
      |                 ~^~~~~~~~~
construction.cpp:145:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  145 |     for(int i=0;i<w.size();i++){
      |                 ~^~~~~~~~~
construction.cpp: In function 'int main()':
construction.cpp:165:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  165 |     for(int i=0;i<s.size();i++){
      |                 ~^~~~~~~~~

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