Submission #1109021

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109021		doducanh	Factories (JOI14_factories)	C++14	100 / 100	3233 ms	355500 KiB

factories

///breaker
#include<bits/stdc++.h>
#include "factories.h"
using namespace std;
#define ll long long
#define fi first
#define se second
#define ii pair<int,int>
#define mp make_pair
#define in(x) freopen(x,"r",stdin)
#define out(x) freopen(x,"w",stdout)
#define bit(x,i) ((x>>i)&1)
#define lc (id<<1)
#define rc ((id<<1)^1)
const int maxn=5e5+7;
const ll inf=1e18+7;
vector<pair<int,ll>>adj[maxn];
int sz[maxn];
bool used[maxn];
int p[25][maxn];
ll minn[maxn];
int h[maxn];
vector<pair<int,ll>>ancestors[maxn];
int dfs(int u,int par)
{
    sz[u]=1;
    for(ii pp:adj[u]){
        int v=pp.fi;
        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(ii pp:adj[u]){
        int v=pp.fi;
        int w=pp.se;
        if(v==par||used[v])continue;
        dfs2(v,u,cen,depth+w);
    }
}
int getcen(int u,int par,int treesize)
{
    for(ii 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));
    used[C]=1;
    dfs2(C,-1,C,0);
    for(ii pp:adj[C]){
        int v=pp.fi;
        if(v==par||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({B[i],D[i]});
        adj[B[i]].push_back({A[i],D[i]});
    }
    buildcen(0,-1);
    for(int i=0;i<N;i++){
        minn[i]=inf;
    }
}
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;
}
/* stuff you should look for
 * int overflow, array bounds
 * special cases (n=1?)
 * do smth instead of nothing and stay organized
 * WRITE STUFF DOWN
 * DON'T GET STUCK ON ONE APPROACH
 */

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