Submission #1109018

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109018		doducanh	Factories (JOI14_factories)	C++14	100 / 100	3600 ms	354536 KiB

factories

#include <bits/stdc++.h>
//#include "factories.h"
using namespace std;
#define ll long long
#define fi first
#define se second
const ll MOD = 1e9 + 7;
const ll N = 5e5 + 2;
const ll inf = 1e14 + 2;

vector<ll> minn(N);
vector<int> sz(N), used(N, 0);
vector<vector<pair<int, ll>>> adj(N), ancestors(N);

int n;
int dfs(int u,int par)
{
    sz[u]=1;
    for(pair<int,ll>pp:adj[u]){
        int v=pp.fi;
        int w=pp.se;
        if(v==par||used[v])continue;
        sz[u]+=dfs(v,u);
    }
    return sz[u];
}
void dfs2(int u,int par,int cen,ll depth)
{
    ancestors[u].push_back({cen,depth});
    for(pair<int,ll> pp:adj[u]){
        int v=pp.fi;
        ll w=pp.se;
        if(v==par||used[v])continue;
        dfs2(v,u,cen,depth+w);
    }
}
int getcen(int u,int par,int treesize)
{
    for(pair<int,ll> pp:adj[u]){
        int v=pp.fi;
        if(v==par||used[v])continue;
        if((sz[v]<<1)>treesize)return getcen(v,u,treesize);
    }
    return u;
}
void buildcen(int u,int par)
{
    int C=getcen(u,-1,dfs(u,-1));
    dfs2(C,-1,C,0);
    used[C]=1;
    for(pair<int,ll> pp:adj[C]){
        int v=pp.fi;
        if(used[v])continue;
        buildcen(v,C);
    }
}
void Init(int N, int A[], int B[], int D[]) {
    for (int i = 0; i < N-1; i++) {
        adj[A[i]].push_back(make_pair(B[i], D[i]));
        adj[B[i]].push_back(make_pair(A[i], D[i]));
    }
    buildcen(0, -1);
}
long long Query(int S, int X[], int T, int Y[])
{
    for(int i=0;i<T;i++){
        for(pair<int,long long> y:ancestors[Y[i]]){
            minn[y.fi]=inf;
        }
    }
    for(int i=0;i<S;i++){
        for(pair<int,ll> y:ancestors[X[i]]){
            minn[y.fi]=min(minn[y.fi],y.se);
        }
    }
    ll ans=inf;
    for(int i=0;i<T;i++){
        for(pair<int,ll> y:ancestors[Y[i]]){
            ans=min(ans,minn[y.fi]+y.se);
        }
    }
    return ans;
}

Compilation message (stderr)

factories.cpp: In function 'int dfs(int, int)':
factories.cpp:21:13: warning: unused variable 'w' [-Wunused-variable]
   21 |         int w=pp.se;
      |             ^

• Subtask 1: 15 / 15
• Subtask 2: 18 / 18
• Subtask 3: 67 / 67