Submission #1232359

#	Time	Username	Problem	Language	Result	Execution time	Memory
1232359		alexander707070	Petrol stations (CEOI24_stations)	C++20	36 / 100	44 ms	14916 KiB

Main

#include<bits/stdc++.h>
#define MAXN 70007
using namespace std;

struct edge{
    int to,cost;
};

int n,K,a,b,c;
long long ans[MAXN],sz[MAXN];
vector<edge> v[MAXN];

void calc(int x,int p){
    sz[x]=1;

    for(auto e:v[x]){
        if(e.to==p)continue;
        calc(e.to,x);

        sz[x]+=sz[e.to];
    }
}

void dfs(int x,int p,int up,long long d){
    
    if(d<0){
        ans[p]+=sz[x];
        d=K-up;
    }

    for(auto e:v[x]){
        if(e.to==p)continue;
        dfs(e.to,x,e.cost,d-e.cost);
    }
}

void solve_slow(){
    for(int i=1;i<=n;i++){
        calc(i,0);
        dfs(i,0,0,K);
    }

    for(int i=1;i<=n;i++){
        cout<<ans[i]<<"\n";
    }
}

int ed[MAXN],m,to[MAXN];
vector<int> tree[MAXN];
int ver[MAXN];

void dfs2(int x,int p){
    for(auto e:v[x]){
        if(e.to==p)continue;

        m++; ed[m]=e.cost;
        ver[m]=x; ver[m+1]=e.to;

        dfs2(e.to,x);
    }
}

void dfs3(int x){
    sz[x]=1;

    for(int i:tree[x]){
        dfs3(i);
        sz[x]+=sz[i];
    }
}

void solve_line(){
    for(int i=1;i<=n;i++){
        if(v[i].size()==1){
            dfs2(i,0); break;
        }
    }

    int pt=1,sum=ed[1];

    for(int i=1;i<=m;i++){
        while(pt<m and sum+ed[pt+1]<=K){
            pt++; sum+=ed[pt];
        }
        to[i]=pt+1;

        sum-=ed[i];
    }

    for(int i=1;i<=m;i++){
        tree[to[i]].push_back(i);
    }
    dfs3(n);

    for(int i=1;i<=n;i++){
        ans[ver[i]]+=(long long) (sz[i]-1) * (n-i);
        tree[i].clear();
    }

    reverse(ed+1,ed+m+1);
    reverse(ver+1,ver+n+1);

    pt=1; sum=ed[1];

    for(int i=1;i<=m;i++){
        while(pt<m and sum+ed[pt+1]<=K){
            pt++; sum+=ed[pt];
        }
        to[i]=pt+1;

        sum-=ed[i];
    }

    for(int i=1;i<=m;i++){
        tree[to[i]].push_back(i);
    }
    dfs3(n);

    for(int i=1;i<=n;i++){
        ans[ver[i]]+=(long long) (sz[i]-1) * (n-i);
    }

    for(int i=1;i<=n;i++){
        cout<<ans[i]<<"\n";
    }
}

int main(){

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

    cin>>n>>K;

    for(int i=1;i<=n-1;i++){
        cin>>a>>b>>c;
        a++; b++;

        v[a].push_back({b,c});
        v[b].push_back({a,c});
    }

    if(n<=1000){
        solve_slow();
    }else{
        solve_line();
    }

    return 0;
}

• Subtask 0: 0 / 0
• Subtask 1: 18 / 18
• Subtask 2: 8 / 8
• Subtask 3: 10 / 10
• Subtask 4: 0 / 12
• Subtask 5: 0 / 17
• Subtask 6: 0 / 35